I wonder why some folks have an issue hearing "patches welcome". In my experience when something like that is said, it's a maintainer signaling that they want the feature, but don't have the time or energy to implement it themselves.

To me, that's just something that's a part of free software development. The person trying to work on something in their spare time isn't going to be able to write every feature on their own. So, why do people think it's some sort of hostile statement?