I guess it's all in the delivery

On the comics page of the local newspaper today, Charlie Brown, in the "Peanuts" comic (The strip on the "offical" site was different than what was in the paper, otherwise I'd just have posted the actual strip) says, "I know I'm not the only person who never gets any love letters. There must be millions of people all over the world who never get any love letters. I could be their leader." All the while laying down in misery with his head perched on a mailbox post.

Why is it that when Charlie Brown says it, it's cute and endearing, and when somebody like Kurt Cobain says it, it's whiny, depressing and cynical?