Self-promotion is the very idea of political strategy. If you're against it, you can't really take one politico to task for using it unless you take them all to task for using it. That's almost like saying there's something wrong with summarizing one's resume in comparison with the opposition's resume. Happens every day in politics. ~
Let’s not play semantics. He was successful in his goal of attaining the WH. He won the election, using the method you said cannot work. It sucks, but it is what happened.