As a movement. People have to eat.
There was never any centralized open source movement. Just a bunch of people making open source software for various reasons. Some joined related communities, while many didn't. Some got paid, while many didn't. Some did it as a hobby, while many didn't.
Software is essentially worthless once it exists. Even if many people and many businesses rely on it, there may not be any economic value in maintaining it. If you need to get paid, you may have to do something else for living.
People eating is not a software problem, it's a capitalism problem. Code just sits on a server, and in 99% of circumstances the costs of retrieving or modifying it is negligible enough to copy it.
What you're describing is where the interests of commercial users and free contributors diverge. When that doesn't align, commercial users have to tow the line. If they can't make that work, that's not Open Source's fault.
When you have a product with very low marginal cost of production, the market price for the product often tends towards $0. If you have a business that sells software licenses and someone develops a viable alternative (for whatever reason) and starts distributing it for free, you may have a hard time competing against them. And if the free alternative gains enough market share, both parties may find it difficult to pay for continued development. That's just how the market works.