The key to this discussion IMO is "U"... not where they got drafted, not what they did in the NFL but what they did in college. And no school has been the record-breaking QB factory that BYU has. Period. It's that simple.
But if you must bring the NFL into it, I don't care where you get drafted. Anybody can be drafted high and we've seen how inexact a science the NFL draft is over and over. But find me another school who has two former QBs with superbowl rings. There might be others but not many.
A lot of people use the "system" argument against BYU. I really hate that stupid argument. As if there are no "systems" in the NFL. And how many of former Cougar "system" players and coaches have gone on to sustained success coaching in the NFL and other universities? Of the top of my head... Holmgren, Reid, Belichek, Billick, Crowton, Chow, Sarkesian... the list goes on and one.