Sure, I don't think MM is blameless, but I think when people unfairly gave him the the "QB guru" label because he had developed Aaron Brooks once upon a time they expected we would see Brunell, Hass, etc. come through the system. Maybe he was satisfied with Graham Harrell? I don't think we saw a Mark Brunell come through the system because Holmy probably didn't make Brunell a franchise QB, he was a good QB who probably would have been successful regardless of where he went.
Andy Reid is probably the top QB guy in the NFL, arguably, but who was his best true backup QB (meaning not Mahomes 1 season as backup) in his career, Michael Vick? Chase Daniel? It's so rare to hit on a true franchise QB as it is if you aren't picking in the top 10, it's so unlikely to find a backup QB that is competent enough to not lose games. Moral of the story: Kizer is unfortunately probably the best use of our money at backup QB right now. We could overpay for a former starter, but unless he's Nick Foles caliber then we're fukked either way.