If you look at more recent history, then the college/HS pitching argument doesn't work. The success rate is within 3% of eachother. Its when you start looking to pre 1998 that the college/HS argument really works, but things have changed significantly in development of high school arms since then.
We can disagree about Bailey. I think the Reds are feeling pretty good with that pick right now. When he has been healthy, he has been pretty good this year.... albeit it has just been 23.2 innings of healthy baseball, but it has been good stuff with a 3.42 ERA, 0 HR and just 17 hits allowed.