Childish isn't the word.
When MoP got announced, I immediatly felt it wouldn't please me, and it didn't. I don't hate it either, but it just feels too different to me. (Even though I usually welcome change with open arms)
To be fair, I didn't really like vanilla, when it was more about the Horde/Alliance conflict, and I still don't like it. I always had the most fun when fighting against the legion, or the scourge, including in the original WCs. But it's just me, and I can totally understand some people like it. (Or hate it)