It's more nuanced than that I'm afraid. I work on tooling for a living, and have in fact tried to contribute back to babel but unfortunately there's so much noise and traffic that there's just as good a chance that your PR is stuck in limbo forever than being merged or even reviewed. I understand why, there's only so much the maintainers can do with the limited time they have, but my point is that you can't just say that the problem is that people aren't contributing. It's a two-way street, and maintainers need to figure out how to actually accept (or reject) contributions as well.
There are other ways to contribute than opening PRs and issues of course, like sending money. But even sending money isn't without complexity -- plenty of companies have the ability to contribute financially, but they can't because they need a VAT receipt or invoice to make it happen. Accounting is a hard requirement for companies, you can't just send money willy-nilly like you can as a private person. It's surprisingly difficult for companies to contribute financially to most projects, and that's not even considering the hard ship of getting those expenses signed off which is often a battle and a half on its own. Babel has a decent set up, but still requires a credit card -- this alone makes it much harder since you'd probably have to personally expense it and then try to get it past accounting.
It's a problem, for sure, but I don't think it's as black and white as you make it seem.