Couple of thoughts, acknowledging the fact that not everybody feels this way:
1. You have to get away from the mentality that life is about building up a pile of money. The pile of money does not exist for its own sake. It exists to serve your life. I think it's easy to get sucked into the daily habit of excitedly watching your numbers tick ever upwards on the net worth trackers, and forget what those numbers are actually for.
2. Most people, myself most definitely included, find that having a child is an incredibly rich experience that deepens meaning and purpose in their life. It takes a while for this feeling to kick in. At least it did, for me. When I was pregnant with my first, it just seemed like a huge drag. The baby was planned because on a rational level I knew that having children was something I wanted to do, but it was one of those things that was like going to the dentist--"this is the right thing to do but I sure don't feel like doing it." I didn't feel like putting my body through pregnancy, didn't feel like putting our mega savings on hold, and definitely didn't feel like dealing with the huge curtailment of freedom and fun with my husband that having a child would entail.
That feeling didn't wear off with my son's birth. If anything, it actually got worse. Newborns are not very charming when you have a dentist mentality about them.
Fortunately, my underlying belief that having a child would be something that would be worthwhile in the long term turned out to be correct beyond my wildest imagination. The kid grew. He started getting cute. I started getting used to sleep-deprivation. My husband started stepping up. We had some tough conversations and learned to love each other better through the relatively small hardship that having a kid represents. And our friends and family came through for us. $1500/month daycare kinda got absorbed into the budget and we found we were still able to save quite a bit.
Had another kid, a girl this time. Fun right from the start. Even pregnancy wasn't so bad. Didn't feel like the dentist. Just felt like an incredible adventure. More money for daycare? Cool, take my whole wallet. I don't care anymore. I have these two little kids to love. Worth much more than a pile of money growing larger by the month.
3. Saving for college is a small priority for us. We got a gift of $25k from my uncle right before our first was born, and we threw $10k of it into a 529. Since then we've been putting $50/month in, and my mom gives the 529 a couple hundred for birthdays and christmas. That's going to be the extent of our college savings for both kids--about $1000/year on top of the $10k at the very beginning. Not enough to cover everything, for sure. Our strategy is to pay off our mortgage by the time the first is a freshman in high school, and when the kids are in college we'll have enough savings for about 1/3 to 1/4 the cost of college. Without rent/mortgage, and considering the fact that our projected net worth should be around 1.5 million by then, we figure we can cash-flow the rest.
4. Daycare is horrible from an expenses standpoint. It's also very time-consuming to find a good option that is reputable AND an acceptable commute. We've had great luck with care.com and also tapping into an extensive social network to find good caregivers. Right now I lucked into a wonderful situation with a work friend of mine who gave birth to her first about four months after I had my second. She didn't want to go back to work, so she's babysitting my second for $250/week (I'm a teacher and get a lot of time off, and it's hard to find childcare arrangements that are ok with you taking the kid out during school breaks and not paying them. She's ok with it: huge savings for us). She happens to live right at my job, so I just park and walk the baby over to her house. Mamas who want to make extra money by taking in an extra kid can be a great, affordable option. Yeah, a little sketchy, potentially. You have to really put the word out and work your social contacts. We've had three such mamas over the years and they've been amazing, though. So it can be done.
5. Our life goals don't include early retirement. We save a ton of money, but we also give about 18% of our gross income away because that's one of our core values. I mention that because our paradigm is a little different--we see our jobs and our children as integral to a rich, meaningful life. We don't see our jobs as a distraction from what we really want to be doing with life, so it's not a priority for us to get away from our jobs. So seeing the ~$2k/month fly out the door for childcare isn't quite the gut-punch it would be if our paradigm were early retirement.
That being said, I've found that it doesn't pay to get into a scarcity mindset when it comes to worthwhile things in life. Mustachians are used to having a scarcity mindset--hey, don't buy that shiny new gewgaw, it's not worth the money when you compound that price over years. If you buy that shiny thing, you won't be able to afford the things that really matter. Scarcity. There are only so many resources to go around. Helpful for silly nonsense purchases that don't add real value.
Not helpful for things that are truly meaningful. When you put money into things that are about more than yourself, somehow the money just adjusts. Daycare gets absorbed. You make more money. Your expenses go down to make room. It works itself out. Having a scarcity mindset about everything just leads to...scarcity.
That's kind of woo, but I'm sticking to it.
TL;DR: When you have a kid, motivation grows and changes. It works out. Most people find it to be worth it, at least in the long run.