Please correct my history if I'm wrong as this all very secondhand. But my understanding is that O'Sensei didn't want anything to do with money. I'm not sure if this is a cultural thing as my understanding is that women handled money in Japan or if O'Sensei was making a spiritual commentary of some sort.
I believe we generally take it for the latter approach. I've known one instructor who would literally slam the phone down on potential students who asked what the monthly dues were. I always thought this person was nuts but it was their dojo. I also found it slightly humorous when this person would be sweating over money. I'd just keep hearing the sound of one phone slamming.
Having said this, I've also heard that while O'Sensei didn't soil himself with collecting money his wife did. So despite the rhetoric, he got paid.
Money is a method of exchange which allows you to continue offering something of value. I think a lot of the problem is that people have no idea how much it costs to run a dojo. You have insurance, rent, mat expenses, electricity, heat, training (your instructor needs to attend seminars to get better don't they?), accounting fees, maintenance costs then add to that the cost of walking around the earth. It ain't cheap and when one is concerned about money it is damn hard to be centered.
But you should work and run a dojo in your spare time you say. How many of you work 15 hour days forever? I did this for 6 weeks while covering for my sensei (military obligations). He taught at 2 different places. So my schedule was work 9 hours (fortunately I could do an 8 to 5) and teach 3 nights a week for 3 hours (one class mine). Those were the easy days as the other 2 nights I was driving 2 hours (round trip) and then teaching 3 hours. I've said I taught 3 hours, actually that isn't right, you see I also had to be there early to open the dojo then I had to be the last one out, I had to handle new students, make sure things got cleaned up and all the rest of what goes on in running a dojo. I was exhausted.
A solid self-sustaining dojo makes things much cleaner and easier on everyone. I really doubt anyone is getting rich running a dojo. I can think of a couple who are probably doing pretty well but when you can make $65K for pushing the power button on a computer it just don't compare.
Sorry for the rant but pauper Aikidoism is a pet peeve of mine amongst many.