So, going by the number of books and tutorials metric, java is a much more complicated programming language than erlang? Have you seen how many books and tutorials java needs?
Back to the original topic, git is also way more complex than a DVCS needs to be (compare e.g. with monotone, or just about any other DVCS). And any DVCS is way more complex than even the most difficult to use centralized repositories. So I think the OP's point is valid. There is at least corrolation going on here.