I don't think that's any more ironic than it is to point out that LLVM is backend agnostic, yet we always end up hooking it up to backends that lock the end result to a specific architecture. It's not ironic; it's the advantage of the design.

In git's case, its decentralized nature ends up being an advantage because it decouples centralization from the VCS itself, which has allowed the centralized aspects of code and project management to evolve independently and be tuned to specific use cases.