Young lads preferring to do trades and the gender imbalances of school staff bodies are surely universal issues, so can't really be used to explain the specific issues in Armagh. In any case, St. Ronan's won an All Ireland four years ago and St. Paul's have made a couple of MacRory finals in the last decade, so maybe the performances of Armagh schools haven't been all that below par.
The county is also clearly still producing quality footballers. Our current senior panel is the most talented that has been assembled for about 15 years, and almost all of those lads have come through our clubs, schools, and development squads over the last decade or so.
I would suggest our terrible record at underage level since the turn of the 2010s has perhaps more to do with sub-standard management of teams at minor and U21/U20 throughout those years. We haven't had golden crops every year, but there's no doubt some very talented year groups passed through the system without making the impression that their abilities merited. Were the right men always in charge?