Do you have any examples of people (other than you) who have actually done this? It would make your argument much more convincing.
Also, the fact that other DVCS's have different, incompatible models underlying them suggests that Git's nouns and verbs are not nearly as universal as Unix pipes. If Git's nouns and verbs were universal, Git could subsume other DVCS's (ie. you could implement other DVCS's semantics on top of Git with performance as good or better than what they have already).