It's actually sort of an interesting question, there are probably a number of factors. Recruiting territories would be one. Unless we find a unicorn; an in-state QB who can grow to run an FCS team, we have to look further afield. One problem there is that our back yard with lots of population is Washington/Oregon which have powerhouse FBS teams known for throwing the football. Good Idaho kids are probably looking at Boise St or one of the Utah FBS programs.
Pressure from the fan base to win not just right now but always might affect how the staff look at QB's. The Griz fan base don't seem really big on allowing "growing pains" like a couple of 5-6 seasons.
I think you will find in the future that with the new college football realities it is less likely rather than more likely that we see Bobby's program or anybody's program more likely to develop kids who stick for 4/5 years at QB.
Or you may be on to something and perhaps developing QB's is not one of the strengths of Coach Hauck and his staff. Hell, we can't all be good at everything. I for example happen to be excellent at being a potentially gay, soccer playing, Canadian but I'm lousy with DIY projects.