It was a joke from a question a few days ago; the change was never meant to be permanent. However personally I don't feel like you need to know one's name to begin with, several such people in this question alone don't provide it. I can promise that no one actually believed I was the POTUS, nor did I try to impersonate him further than my gravatar/display name.
I never meant to cause a problem, and I still answered questions properly and with maturity. Anyone could just as easily impersonate someone else and no one would ever know (or complain). As the name I chose was obviously not me or anyone else here I thought it was harmless. I think the reaction is a bit overboard myself, but I indented to change my name back anyways, and have done so.