The amount of media playback and serving software out there is innumerable. If most of it doesn't handle some obscure format, that format is screwed.

Getting a new format everywhere is a difficult battle; the adoption barriers are high. Even if the thing is completely royalty free, and comes with a great, open source reference implementation.

Something that is closed, and has no backing of some corporate consortium or ITU type body or whatever, is basically fucked.