It's just the standard. So it self ratifies. It is quite possibly one of the worst options though given how many important language features are lost in it.

Cantonese used to be the preferred, and probably is to some, but even that is far from ideal and was chosen because while it preserves more important distinctions, it also happens to be/have been a very prominent Chinese language, with a moderate level of standardisation. It wasn't chosen purely on its linguistuc merits over others.

I can't remember who it was but there's someone out there who uses a fusion of Cantonese and Hokkien, where they pronounce the initial from one and then the coda from the other or something, though I can't remember which way around they did it.

Really depends on your priorities I guess.