2) The Democratic party's official position is not that superdelegates are a complement to a 100% democratic process but instead that they exist _solely_ to ensure that party leaders are properly seated at the convention and do not have to compete with grassroots activists for participation at the national convention.
I don't personally believe that (2) is a good-faith defense of what superdelegates are, but that is the DNC's position. And it's worth mentioning that there are valid reasons for superdelegates: how do you deal with a potential nominee like John Edwards, what if the convention is truly contested (with 3+ candidates and no 1st-ballot victory?).
The Republican primary went largely as it should have been, and arguably Trump should have received an even larger share of the final delegates. Voters expressed their preference and that person became the nominee (whatever I think of their preference is irrelevant).