I don't hate the project at all. I just don't see any benefits to switching. Honestly I already find mplayer bloated, as all I expect from a video player is to play/pause/seek, and optionally buffer input (not even required, as tee(1) do that well enough).

If mpv break when called with a link to a .mp4 video directly, because of youtube-dl API changing or whatever, then that is one more reason for me to keep using mplayer ^^ At least I know that it does not try to be too smart and simply download/decode the data stream on the fly. If I need youtube-dl in the pipe, I'll add it myself.