This was beaten to death back in the early days of Classic. You should use the search function or look around this sub-forum (although it may take time to find this). Theymos has stated their reasoning, and they do not agree with those 'implementations'.
It's easy to claim you have consensus when you are censoring all competition. But I'm sure if other clients were given equal chance, the consensus would shift towards one of them.
Shift towards what exactly, an implementation that has even a much smaller team and even less peer review like Classic? IIRC theymos labeled it as an altcoin back in the day.
BU may be different. Last time I checked they didn't have a faulty fork proposal implemented(?).