USH in this country does not go deep by design, because the purpose isn't to educate, it's to mold compliant citizens.
I think it's impossible to make broad generalizations like this. The first book dd read in APUSH was Zinn's "A People's History." Hmmm.... doesn't really seem like they were trying to mold compliant citizens!
I took it in high school. Homework was full of the same kind of rote nonsense mentioned here, which is why nobody did the homework. Tests had it, too. I used to get about 70% of the questions right... and set the curve.
This would never have happened in dd's class. If you didn't do the homework, starting with the reading/analysis due on day 1 of class, you were kicked out. And the class wasn't curved....
So, needless to say, I was worried about the AP test. I got a 5.The instructor made all the difference. He made up for awful textbooks and test questions. Of course, ultimately it was still a really bad course, but that's not his fault.
So, what do you mean "it was still a really bad course?" The AP program doesn't set curriculum. Each HS develops its own curriculum. Dd's course was not full of rote nonsense; it was one of the best courses she ever took in HS. She didn't do rote nonsense and she didn't memorize thousands of dates or spend hours reviewing, and she got a 5. You didn't do the "rote nonsense" although your HS apparently included it in its (not AP's) curriculum, and you got a 5. Seems like a good teacher/HS can develop a curriculum that is not full of memorization or regurgitation and still have its students do well. The fact that 85-90% of the students (most who are at least high-achieving if not gifted) don't get 5s means, to me, that most teachers don't do a good enough job.
I'm sure I made it obvious that, except for the first paragraph about US History in general, I was speaking of personal experience. Your results, quite obviously, may vary.