Sometimes it's better to be lucky than good.
I think to a certain extent finding a true franchise QB is luck for just about everyone. One, you never know how these guys will pan out. Many times (MANY) even the guys drafted really high don't pan out. Some because they are vastly overrated coming out, some because of the situation they end up in, some due to injury etc etc.
Take us with Aikman for instance. Everyone knew that 1988 season he was far and away the best QB prospect in that class and one of the higher regarded prospects coming out in several years. Going into the final week of the season, Green Bay actually had the #1 pick and we had the #2. All Green Bay had to do was lose on the road to the Cardinals, who were 7-8 and were heavily favored. A Green Bay loss ensured the #1 pick. Instead Green Bay won (it was actually their 2nd straight win) while we got beat by Philly. We ended up with Aikman, they got Tony Mandarich.