In all the companies I have worked through my career thus far, not a single one has contributed back in any form to the pile of FOSS libraries that they were using.
My team at EvilCorp contributes fixes to several open-source libraries. The reason this happens, though, is that two of our stronger devs said "the correct thing to do is to take the time to get these fixes into mainline," which they did. The answer to the question of "why" we do it isn't "because it increases our team velocity," but because we're software engineers, and that's what good software engineers do whenever possible.
On my case that would be the path to be fired.
In none of the companies I worked for, doing that would work without going though legal and all the necessary layers to green light it.
5 of them are over a year old. Most of them had no review by the development team, and many of those that did, got stuck on Bill, for instance, trying to get Travis enabled: https://github.com/findbugsproject/findbugs/pull/48#issuecom...
There is no incentive to contribute to a project in such poor shape.
SonarQube abandoned FindBugs mainly because it was low on activity:
"FindBugs project activity: The activity on the project is quite low and thus the value coming out of it does not come fast enough to satisfy our users."
http://www.sonarqube.org/sonarqube-java-analyzer-the-only-ru...
On that very email chain, once the sitution was stated and as Bill kept on ignoring everyone as he did over the last year and a half, the community hard forked FindBugs and started aligning behind https://github.com/spotbugs/spotbugs
Bill's reappearance is now puzzling. To abandon the fork to go back to FindBugs would require major leadership changes, as confidence on Bill has been shattered. Keeping the fork leaves the project on the same point people tried to avoid in the first place.
Sounds like quite a few precautionary tales in this one.
Most successful projects in FOSS with many downloads get virtually no contributions or financial support back. Even the largest ones have an enormous user to contributor ratio with almost all benefits going to the users. Therefore, it's the status quo for open-source in general. Those getting tons of contributions and development without a company behind them are extremely rare.
I had a great article on this before my crashed HD deleted newer bookmarks. It was a woman that surveyed many popular projects to ask about their status. Most complained they were barely getting by, the developer(s) stretched thin, tons of requests without accompanying payment/support, and mostly no contributors. I'd like a link to that article if any readers know which one I'm talking about.
She never ended up finding a solution to the problem and instead ended up joining GitHub as a opensource developer advocate (or something similar to that).