"This doesn't sound like a person who can write something halfway as thoughtful as the film Juno. This is a person who is ignorant and shallow."

I think it would be easy to agree with you if I thought Juno was halfway as thoughtful as you seem to think it is. For me, it's all-to-plausible for me to imagine someone like Diablo Cody writing Juno because I find the script shallow, unimaginative and unfunny.