Look at the actual classes, though. They were "6th" in 2016, but their average stars were 0.01 behind Texas Tech. They had an average star 0.31 better than WVU, but took 6 fewer players. So, really, they were 4th behind UT and OU and TCU for a year. In 2015 they were (again) 0.01 in average star behind the team ahead of them and then WVU, OU, and UT. Again in 2013 there were 5 teams in the Big 12 (behind UT and OU, as always) within 0.11 in average stars and Kansas was "ranked" last of those teams despite the highest average stars.
Oklahoma State has done a good job beating everyone, except OU and UT when they aren't a complete dumpster fire turning over HCs, they are competing with and should beat. That's great for them, but they play in a conference where only 2 teams recruit better than they do and one of them has been down hard for the last 5 years.
In Pitt's case, we play in a much more competitive conference. We have to (at a minimum) be even with Virginia Tech, Miami, and UNC. If we don't we have to pull upsets (on talent) AND beat much more talented teams with very stable HCs and staffs from FSU or Clemson to win our conference or get a major bowl. OOC we have to face teams like PSU and ND with much more talent, as well. So, for Pitt to have a 10 win season in the ACC, we probably need to pull at least 2 upsets (out of generally: 1 OOC, 2-3 in division, and maybe 1 rotational ACC opponent like FSU or Clemson) and win all the games we play against the same or lower level talent. Oklahoma State probably doesn't have to pull a single upset to go 10-2 and maybe not even one to go 11-1, if you consider the turmoil leading the talent at Texas. Also, they only have 1 Big 12 championship.
So, sure, if we are similar to OkState in terms of upsets vs. more talented teams and pull off one (or none) a year, we can win 8 or 9 games (assuming we also win all the other games) most years. Because of their conference and schedule, they can win 9 or 10.
As others have said, finding QBs is a big part of it, too.