To be fair, the "dumbing down" of instruction isn't limited to PADI specifically, or the mass-diving instruction agencies in general. It's widely permeated our entire culture, from our public schools right through many higher education institutions. Many traditional colleges and universities report having to run freshmen through what amounts to remedial English and Math courses, because too many high school graduates today are functionally illiterate and mathematically clueless. The schools couldn't fail them, though, because it would look bad on the metrics and might hurt the child's self-esteem.
I would not care to guess just how many management and engineering types we have here at work that have degrees, but you could never tell by the virtue of their applied knowledge. Some institutions have adopted the policy of, "if you pay your tuition and show up for class on a regular basis, you pass."
I've often asked people how they would like their surgeon to have learned medicine the University of Phoenix Management Program way, which is "learning by committee." You're on a team, and if one person on the team does the work, the whole team gets the grade.
Just imagine how bad dive safety statistics would be if PADI or any other agency adopted that model. "If one person in your OW class does the work and makes the dives, you're all certified."
Our choices here in Tucson are PADI through one shop, or SDI through the other, and from what I've seen, there isn't much difference between PADI and SDI as far as depth of curriculum. We're going through PADI, but I'm definitely looking for far more information from other sources than just the appetizer the PADI books offer.