The community user is not a real user. It is just a bot that perform many automatic actions in SE sites. So, in fact it doesn't need any reputation at all.
It will not post any question nor any answer in non-meta-sites. It used to post an automatic generated question on site's metas very ocasionally and answer it with an automatic answer, but I don't think that it does this anymore.
Without questions or answers, it will not have any use for reputation. Also, it will not vote for or against anyone (but it may own votes given from deleted users, serving as a placeholder/fake voter).
So in fact, whatever reputation is shown for the Community user, it would be meaningless. In my opinion, I think that SE should not show anything at all as reputation to the Community user. Or perhaps, should show a text in the place of the reputation something like "StackOverflow bot".