It's not an either or scenario. Many different things can be true simultaneously.It's real.
Fran is not stupid. If you are unable to consistently recruit at the top of the league, there are a few ways to remain competitive. One is to limit possessions -- the Wisconsin way. The other is to put shooters everywhere on the floor and try to outscore every team. 3 star catch and shoot shooters ain't playing lock down D, and they ain't dominating the glass.
If Fran had a .500 record playing buckyball after 15 years, do you really think there would be anyone left in the stands? Me either.
What you're saying is obviously a factor but not the only factor.
Fran isn't stupid but he is kind of eccentric. He's hyper focused on offensive efficiency.
He's had good defenders that he doesn't play because he wants everyone on the floor to be an offensive threat.