Outside of the real "big boys" in the industry (and that's pretty much Wizards of the Coast/current incarnation thereof, Paizo Publishing, and White Wolf/Paradox) there really is no significant RPG publishing industry. There is a smallish vanity press system which has made exclusive and heavy use of print on demand and probably been one of the driving forces that have made POD a going concern for many years, but realistically – that's it.

It's a very tight, very small, extremely niche form of entertainment, and it actually always has been. Compared to most other creative industries, it just doesn't even appear on the radar. While the new "let's play RPGs in public via live stream" thing is a real thing, you'll note that most of it is focused on products of the big three and maybe, occasionally, something just a half-step out of the mainstream to the side.

But it's always been that way, and some people have managed to make real careers out of writing in the industry. Not huge careers. Not big stacks of money careers. But careers that feed their family – most of the time.

Unless you are Dungeons & Dragons, Pathfinder, or World of Darkness – there will come a time when you can't afford to put money and time into development. That is the nature of the beast. If you're very, very lucky, you'll cultivate a very small fan base who wants to carry on the project and the product and it will become mostly self-sustaining for a while but not forever.

The nature of the beast. As long as you accept that it is what it is, you can stay ahead of the curve and relatively psychologically happy.