Loan Officers get a percentage of the loan amount, and it's not rare for them to make $300k/year in a good year.
Its the same with real estate agents, a good one can be very wealthy. Some LOs hit annual comp > $1M, though that is rare. I found it pretty shocking when I first found this out.
Send me an email if you want to make the market more efficient, I'm working to build a modern mortgage bank :)