Whoa, let me rephrase that. Just re-read what I wrote, and that didn't sound right.
I meant that reference to the schools in my area, not everyone in general. I can't speak for places I haven't lived in. I just edited my past comment to reflect this.
Lots of parents in my area (including my in-laws) sent their kids to Catholic school as a way to protect their kids from the 'evils' of public school. I think this was out of fear more than the desire for a better education. My wife did her entire pre-college education in the Catholic school system, and her experiences where no less worse than my public school upbringing. Drugs, violence, teen sex, affairs with teachers, etc. were just as common. Only difference was the uniform.
By the way, my step son just finished High school with Algebra 1, 2, 3, Geometry, Calculus, and Trigonometry ; none of those where Advanced Placement or college prep classes. This was at our local crappy public school, nothing to be very proud of. We have lots of wealthier neighboring towns with public schools that resemble private institutions (and property taxes that match!). Can't imagine what their students are learning.