The problem has never been the drafting of Dak Prescott, he was an historic 4th round pick.
The real problem was his contracts, the absence of genuine competition at the position and the attempt to turn him into something he wasn't.
Dak wasn't a gunslinger, he was a very capable bus driver so long as the offense had their strong lineup. They should have continued to use him the way they did his rookie season.
They also should have made a point to acquire an alternative instead of behaving as if the QB position was set for the next 10 years. This would have also given the team leverage during contract talks.
Any negative feelings about Dak should be directed towards management.