I don't see syllabus PA's as a big issue or something that's really happening all that often. Sure you can have a guy who washes out of IFF for something airmanship related, and it's easy to point at a training anomaly a year earlier. But that doesn't mean they are related necessarily.
Having said that, when you look at the gradual erosion of the syllabus over 10 years combined with PA's you could easily understand how a general decrease in airmanship is happening. Just speaking anecdotally, when I went through UPT I had 17 solos. 5 in the T-6 and 12 in the 38. Nowadays students get half that. On top of that, there has been a reduction in total flight hours of ~20% in the last 5 years with no added sim time.
This is happening because any single syllabus event can be argued out of existence by the good idea fairy.
It starts at a syllabus "conference" when someone says: "students don't learn anything new from that second T-6 MOA solo anyway. We'd make a few days up on timeline if we just get rid of it." And before you know it you've lost half of all student solos, ELPs, fix-to-fixes, T-38 form-solo O&B, wing work up to 90 degrees, over the tops in ET, perch setups, VFR nav leg on XC, formation sim, advanced contact and formation for all T-1 bound students, and the motherf-ing chandelle.
Okay maybe the form sim was useless, but you get my point.