I completely disagree with the ludicrious notion that Bruce Irvin ISN'T a LEO.
In as few words as possible,
#1: He has to sell out in the pass rush to get pressure. This is not news.
#2: He has to sell out to stop the run and is still a liability despite that.
#3: He can't sell out to rush the QB AND sell out to stop the run. For Irvin, it's a zero sum game.
#4: His size, build, strength, and most especially technique do not paint a rosy picture for growth against the run. This is why Irvin was not a top 5 pick. Completely serious, he plays 3-down DE about as well as Bobby Wagner would, and probably less well than KJ Wright would.
#5: Irvin is a high exertion player. Hustle is the name of the game for him. Playing every third down in a pure pass rush situation benefits him. He would take downs off or tire out in an every down role.
#6: He has been a non-factor in a 3-down role throughout the season. The only exception was the 4th quarter of the Redskins game, but that was masked by frequent blitzing which aided Irvin tremendously.
Even if he was the LEO, we'd need to find a new Raheem Brock to replace Irvin anyway. Why not just upgrade LEO instead and save ourselves from a massive problem? I guarantee you that Irvin will not be our LEO in 3 years time. Pete will get his horses on that D-line, and Irvin will remain a valuable situational rusher.