The official reason is that the "internals of Git" weren't conduce to the kinds of invasive changes they needed/wanted. But I think the truth is closer to being

The official reason is that the "internals of Git" weren't conduce to the kinds of invasive changes they needed/wanted. But I think the truth is closer to being that it was going to be too hard/slow to get those invasive changes past the Git mailing list. Funny, but I'm starting to wonder if there's an affect-based complement to Conway's Law.