That's a pretty broad brush you're tarring all FOSS creators with. I don't accept it. I've worked with a number of Home Automation software publishers who have literally fallen all over themselves to fix a bug or issue that I identified and do it very quickly. If they couldn't fix it right away because of some complex dependencies elsewhere in the code, they'd certainly file it away in their "we'll get to it at the next major build."
Interestingly enough, when I asked for features that would benefit mostly me and not all the other users, I always got the "we'll see" which is parent-speak for a deferred "no." "Can I have a BB gun for Christmas?" "We'll see."
If you told me that, as the guy who hired you, I would simply say "It's unfortunate that you used tools that were unsuitable for the task. Didn't you evaluate them fully before starting?" Whose fault is it then? The poor FOSS creator who's doing it as a labor of love or the guy trying to save a buck by using FOSS on a paying project?
I rarely bring freeware onto a paying project but if I do, I make sure it's functioning and that it can be properly licensed by the end user.
I've never had an issue with IrfanView, VLC, HexEdit, WinZip, PKModem (in the very old days) and so many more products that I have just the opposite view of FOSS than you have. What FOSS program burned you so badly that you're willing to classify them all as drek?