It’s easy to get pressured into thinking it’s your responsibility. There’s also the risk that an unhappy company will make a non-copyleft clone of your project, pump resources into it until it’s what everyone uses by default, and then add proprietary extensions so no one uses the open-source version anymore, which, if you believe in the ideals of Free Software, is a bad thing.
It also doesn’t help that once you’ve paid the large fee for the Pro version, it doesn’t actually guarantee any support if you encounter a bug. You get access to a different issue tracker, and might get a Unity employee to confirm that the bug exists after a couple of months (and maybe close it as a duplicate, then reopen it as not a duplicate when the fix for the other bug doesn’t help, then reclose it as a duplicate when it turns out the fix for the other bug also doesn’t fix the other bug, and at the end of a multi-month process, there still being a bug with no indication an engineer’s looked at it).
Anyway, I’m glad to no longer be working for a company that uses Unity.