Patrick isn't a miss, while his scoring hasn't emerged yet, he's already an above average defensive center at 20.
Rubtsov, Laberge and O'Brien are bad injury luck, but all have shown flashes, far too early to give up on them.
Hextall's worst draft picks were NAK at #48 and maybe Ginning at #50.
Hextall's real problem is he took over a team with limited assets, an depleted talent pipeline (Ghost, Laughton, Hagg, Morin, then scrubs like Cousins, Leier, Manning, VdV, etc.) and no cap room.
We won't know until the stories eventually come out, but I suspect Hextall would have blown it up in the summer of 2014 (trade Voracek and Simmonds) but wasn't allowed to do a rebuild and tank for a few years, the FO wanted to be "competitive."
Hakstol is the fans' whipping boy, but name one prospect who flopped under his watch. Now compare to other teams around the league. That was his most important job, teach kids how to play two way hockey. The next coach is going to inherit a deep, talented and very young team.