Thats the point though, and you're missing it: In FOSS, the maintainer doesnt owe you anything. It doesn't matter what the bug is. Most popular software licenses contain a clause about no warranty etc. for a reason.
Maintainers owe you absolutely nothing for just using their software.
Go pay them if you want them to work for you, and see if they want that.
If a public software is very far off from working as advertised, effectively demonstrating bad faith, if its code is being hosted on a social hosting site, you can bet that I will complain about it to the site, and get everyone else to complain as well. If the software is no longer being developed and has been dead for years, then it's a different story, and the intent then is to move elsewhere. The license file is not an excuse using which to hide lies.
Correct. I think the one thing that is "owed", if that is even the right word, is that you don't knowingly put malicious software out there. But that's it.