Because he can't go through an entire statement without asking a question only to answer it immediately himself. What's that mean? It means he thinks he's encountered a "clever" trope he likes and thinks he improves his speaking by abusing it to death. What's the result? He sounds really stupid.
Am I exaggerating? Definitely not. Every other sentence, almost literally, ends with a question mark.
Don't believe me? Watch for yourself. And you'll start noticing it and getting annoyed just like when you watch Unwrapped and start noting Mark Summers's random, misplaced dramatic pauses.