Yes, that was a bit facetious of me, I apologize for that.
> What is so bad about the existence of this project?
Being very blunt: The fact that it reinforces the extremely common misconception that a) converting between containers like mkv and mp4 will always require reencoding and that b) there is a single way to reencode a video (hence suggesting that there is no "bad" way to reencode a video), seeing as next to no encoding settings are exposed.