AP US History does not go deep because college US History does not go deep, and as a result, our country has a poor understanding of US History. This is all very topical.
Dude, those are pretty broad generalizations. Many college history courses *do* go deep and challenge students to assess contrasting perspectives. I'm sorry if your courses didn't, but you can't say with certainty that they all don't.
Likewise, I wouldn't assume that AP history in high school reflects college history courses. How could it? There isn't a single standard college history curriculum.
DeeDee