Before I start, do note I'm not trying to take sides (heck, I haven't even heard one side, so I'm out half the information!). Just trying to get you to think about things that maybe you haven't thought about yet.
After tax is likely under $25k. I do recognize that in a lot of the country that's liveable, but I live in one of the most expensive cities in the country (and he is unwilling to move - I've brought it up as an option). I think he's happy with where he's at and how things are going - no goals for the future, just living life day to day. It never used it be that way - he had some drive in the companies he worked for, negotiated for higher income, wanted to own a house and save for down payment. Once we got the house and quit his job he turned into a housecat, and that's when things started changing.
Have you brought up radical changes, or easier ones? I.e., are you suggesting to move across the street to save $50k on the mortgage, or are you proposing to move across the country to ONLY have a $50k mortgage? Whichever you've tried...have you tried the other? Maybe he doesn't see the sense in going through all the stress of a move just to save $XX a month...or maybe he doesn't want to move across the country and leave family/friends/clients behind. Did you ask WHY he doesn't want to move?
Thinking about it more, my frustration is really about him not being able to cover our monthly expenses, whether something happened to me, or if I wanted to take time off (like maternity leave). I'd have to look at my budget again, but I think we could cover the necessities on $3-4k a month - but that would mean 0 business spending (and him basically working while I'm on maternity leave). What if we wanted to do it together? I would have to plan for it and save for it myself... It gets pretty lonely having to plan for your future together alone. Now, I'm the first to admit that there were many years where I was probably looking out for my career above everything. I think I even missed his 30th birthday party because I had to work. So in some respects, he might be looking at it that he's doing what he needs to do because that's what I did (and his dad was pretty MIA growing up because of work priorities).
If you're on maternity leave, how will you cover YOUR portion of living expenses? If you've already saved enough that you can cover your half with the 4% rule...that can be turned into a good lesson for him. Could also be turned into a bad one. If you can't cover your portion...you realize that you started the relationship one way (making lots of money) and now want to change (by making zero money as a SAHM). Yes, priorities change...who says your reasons are more valid than his? Even if yours ARE more valid...how does he view it?
In terms of his goals - I can barely get an answer from him about what his goals for this year are, let alone ten years from now. He gets very agitated talking about the future, and that is very frustrating for me - not only on a personal level, but it makes it incredibly hard to plan for anything. There are practical and financial reasons that I'm asking (and I'm not even asking for solutions, but just his opinion)... for example, are we happy enough to stay in our house for five years, or could we move? That impacts the types of upgrades we do to the house, where I put our extra cash, etc. He freaks out if I even bring it up.
Two easy answers for this.
#1. Anytime you start a conversation like this, it ends poorly, so he's trying to avoid it at all costs. I do this very thing, though I've gotten better over time. Seriously, if you "ask" him questions in a confronting tone, and you get upset at his truthful answers...his options are to lie and/or avoid the discussion at all costs. Now, you can't change who HE is, but you can work on yourself...find a book that discusses how to have a discussion without blaming the other party (I can search my Kindle if you need advice, I don't know any titles off the top of my head).
#2. He simply doesn't plan for the future. Lots of personality types don't. I forget which ones plan sooo far into the future, but I know INTJ is one. Maybe it's the NT part, because I think INTPs do and maybe ENTJs do as well. MOST people, when thinking about the future, are thinking weeks or months, MAYBE a full year if they're stretching it. When INTJs think short-term, they're thinking a mere five years into the future; long-term they're thinking 10, 15, even 30+ years out. It's completely possible and NORMAL that he can't think THAT far ahead. In that case, you can tell him a very brief synopsis of what you want long-term ("I want to be FI so I can work or not because that's what I want, and so I can make our children a high priority in my life.") and tell him what he can do to help that ("You can help find ways for us to reduce expenses and maximize income.").
Now, I get the whole "look at the bright side of your situation", and he certainly has his strengths and contributions that are my weaknesses... but when you can't get a spouse on board to even have basic conversations about the future, it gets really old. In his defense, if I were 7 months pregnant, I know he would say, "do we have enough in savings? Do I need to do anything?" So I know he is cognizant and thinking. His hair is on fire long after the fire has already been put out (and maybe that's a good analogy for my life...) More often than not, it comes across as too little effort too late. When I try to bring future things up when it's important to me, it's like pulling teeth.
See above. He may be one of the normal people who have trouble looking that far into the future.
Really, I wouldn't care about him making $20k if he wasn't saying things like "we need a new roof ASAP" (12k), let's redo our piping in the house (3-4k) or "I really want to move to this nicer area across town" (bigger mortgage, need to save for down payment). If he were looking for ways to cut costs and spending so that our money could go further, sure, I'd probably be more forgiving. But the fact is that he's not changing his spending habits til I point it out. The $20k in business expenses doesn't even include the other $5-10k that was spent on house projects he took on.
To be fair, the $5k-$10k in house expenses really shouldn't be counted as a business expense, unless it was solely to help his business (i.e., having fiber run to the house to increase internet speeds and recabling the whole house would count as a business expense; fixing the roof and doing painting should not).
The roof...does it need to be fixed ASAP? Is he offering to do some/all the labor? If so, are you calculating his labor savings towards his contribution to the family? I mean, if he's making $25k after taxes and saving you guys $10k in labor, can he look at it as contributing $35k to the family? If not, why not?
Another thing I'd like to address. He shouldn't be expected to contribute 50% across the board. You're obviously good at long-term planning and probably financial planning, perhaps you'll contribute 90% in those categories. He's good at household repairs and contributes 90% there. That said, there's SUPPOSED to be an imbalance. If you think everything is completely fair, guess what? It's not. We automatically think we do more than we do. If you think you're doing somewhere between 60-70% of all the work (depending on your bias...which DOES exist), then you're near a true 50%, good job!
To everyone saying you should dump him, or there's serious issues...that may be the case, but from what's posted I don't see it. I see an imbalance in earnings and someone who says he'll do what his partner asks of him (again, I don't know if he'll put those words into action). Basically, I see a relationship with similar dynamics as an INTJ paired with a "normal" person. This normal average guy might be willing to help you meet your goals, even if he doesn't share them himself.
Of course, he could be "one of us" and simply doesn't know what to do with his life. Maybe he's seen half of the light (quitting and doing his own thing) and needs help seeing the other side (financial independence). Doesn't quite sound like that's the case, but again, I'm only hearing one side.