I don’t know about other people, but I didn’t vote for Eleven just because this is the eleventh round. I voted for him because I like Two, Three, Four, War, Ten and Twelve better. I do like Eleven, which is why I didn’t vote for him until this round, but he isn’t in my top five.
Childish'? In a sense, nearly every Doctor has a childish moment. Twelve coming out on a tank in medieval times pretending he's a rock star isn't childish? Ten running around having an affair with a blonde girl in 1950s Britain isn't childish teen-romance? Hell, the 2nd Doctor and 4th have a ton of childish moments but they (especially the 4th) are heavily heavily loved by the Fandom. 'Childish' is way to vague a term to justify hating an incarnation.
In other news, should the next round not be starting? It's been days since this one (supposedly) finished.