In many HSs AP courses are really courses in taking the AP exam. If these teachers were qualified to teach a strong college level course they'd be teaching in college.
My daughter went to one of the best Catholic HSs on Long Island. It did not offer a single AP course. She took a classical curriculum of four years of English, Math, History, Bio, Earth Sci, Chem, and Physics, and three years of French. She took Computer, Art, Music, theory and history, and PE. She went to college as well prepped as anyone who took AP course could have been. Scarsdale is going in the right direction.
It's also worth noting that some years ago -- when Scarsdale had a reputation for being one of the best school districts in New York (if not the entire country) -- the local school board got involved in a clash with the state board of regents over some kind of issue related to standardized testing. It got to the point where most parents in Scarsdale kept their kids home from school on the day the state testing was done, and I believe the state relented after that.
I'd have to do some research to nail down all the facts, but this story was recounted to me by someone who lived in Scarsdale at the time.