If the most widespread implementation does it one way, then it becomes standard. Happened with IE bugs, happens these days with Safari and Chrome bugs.
Public does NOT GIVE A DAMN about geeky correctness. If a page fails on FireFox but works with IE, users will accuse FireFox/Chrome and stick with IE. They did. For years. So FireFox and Chrome supported Quirks mode, and still do.
If MtGox fails because of bitcoin technical reasons, well, bitcoin gets bad press.
Either this is taken as an opportunity, or it will be taken as a blow, that's all.
Well, then the public deserves to loose their money. Any system that would shield them from this is a bad system. Doesn't matter how widespread is the non-complaint solution.