> no, I don't need to accept your PR just because you put work in it, you should have checked with me first, before doing it

Which is a bit rude IMO, and not really in the spirit of open source. I never demanded that he accept it. A PR is like "here's some code, let me know if it's ok" not "you should merge this code without question".

Here is what I would have written:

"Hi, thanks for the code but I don't think I want to go in that direction because X Y Z." (he didn't give any clear reasons so you'll have to imagine those).

Anyway he's free to do his thing. I was just explaining why I moved away from that library.