I happen to know the struggle you speak of first-hand. I paid my bills early on in my journey by teaching courses related to the subject matter my project touched upon. Free software has _no opinions_ on the adequate income model for developers who involve themselves in its world. The beauty of free software is that it is agnostic to your kind of ethics-mongering, which is why I have chosen to be so intimately involved in it myself.
We all need to make a living, and I don't have any presumptions over how someone chooses to do it. However, I think you would be better to not force your particular difficulties and decisions on this front on the entire GNU/Linux user base.
Yes, there's a lack of money in Free Software. Yes, there are consequences from that, like the abandonment of certain projects. That doesn't mean non-paying users are somehow guilty of something, that's a poisonous attitude.
All nice and good when it is possible to sell books, consulting services or hide the software behind a SaaS pay-wall that helps to pay the bills, which is absolutely not the case for desktop software unless it is web based applications behind that pay-wall.
Thus preventing any kind of long term business model targeting the GNU/Linux desktop.
Which is yet another reason why many rather target app stores nowadays.