Regarding the division over whether the forum challenges the reader to increase their income: from my perspective, it does, but in a more general and less useful way. When it comes to reducing expenses, the advice is specific and can be acted upon. We love our spending-reducing advice, here, and it's well-tailored. When it comes to increasing income, though, the advice is more like an overview. This is somewhat a consequence of there being a million kinds of jobs and a million careers, but even so, the reader can't use it to figure out if they're on the right track or not. You can figure out if you're doing well on spending, but we don't have an agreed-upon way to decide if a person is using their skills to their best income potential. We just kinda state big numbers and expect people to be inspired by them.
This isn't to say the income-increasing advice doesn't give any direction at all, though. Such advice is generally one of the following: 1) Get a better job, 2) Negotiate with your employer, preferably by leveraging a job offer you got elsewhere, 3) Start a side hustle, 4) Be self-employed, or 5) Start a business. 1) and 2) are essentially the same thing. 3), 4), and 5) are also sort of the same idea.
Personally, I'm a bit stuck on 1 & 2 because I'm in the Mecca of North America for my field, which is an engineering field, and have still hit a wall. I have a median-income position here, but in applying to other companies, I haven't get gotten further than a phone interview--let alone a job offer. This method works for other Mustachians, including MMM himself, who has a blog post describing the job search and interviewing process as something wonderfully encouraging. On the forum, I see stories of people so skilled they control negotiations with the managers of U.S. government departments. So it might work for other members of the forum, too, who have median incomes and are looking to raise the bar. On the other hand, I'm skeptical if this actually works for normal people like me, to be blunt. I've had such a defeating experience with the job search that my perceptions are distorted; it's very difficult to stay calm and non-miserable in the process.
I'm also stuck on 3 through 5--the best thing I can come up with using my own skills would be less than half of the hourly wage of, say, a weekend job working in fast food. However, side hustling is very popular, and on this forum full of people sensible about money, so is starting one's own business. Being one's own boss is empowering, after all.
(This post might come across as personal Complainypants-ing, and that's because...yeah, it is.)