To be clear, I was responding to the situation where someone clearly puts effort in creating a high-quality contribution (a PR or bug report) and the maintainer

To be clear, I was responding to the situation where someone clearly puts effort in creating a high-quality contribution (a PR or bug report) and the maintainer simply ignores them. I think it is the right thing to do to at least acknowledge it and say "Thank you for your contribution! I will review it when I have time". I don't disagree with you or others on ignoring low-quality, low-effort contributions. I get that people have finite energy and time. Taking 5 seconds to say "thank you" when someone has clearly put in the effort, though, is a no-brainer.