Miguel Torres, Frank Mir's favorite fighter.
Many things factor in Torres run at the top.
Torres was a very good fighter at the time, but he just wasn't what he was built up to be.
The talent level at 135 lbs. back then wasn't as stacked and good as it is now and as it was when the WEC began gaining popularity. Torres biggest win before fighting in the WEC was Joe Pearson. Not a knock on Pearson, but he's far from being an elite 135 lb. fighter. That however says a lot about the level of competition that was available to fight at 135 lbs back then and that Torres fought.
Despite being a very good fighter and the best bantamweight in the world for many years, Torres proved he had flaws and holes in his game and that he wasn't that much above everyone else because he severely tested in wars with both Maeda and Mizugaki who he beat by a close controversial split decision in a fight that some fans felt Torres lost.
Also look at Torres wins in the WEC, they weren't elite top level 135 lb. fighters. His best wins in the WEC were against Chase Beebe who's a decent 135 lb. fighter and Mizugaki who's a very good fighter as proven by his success in the WEC and UFC.
In the WEC, Torres beat Jeff Bedard who isn't even around the major scene anymore, Maeda who's a decent fighter, but not an elite level bantamweight and Manny Tapia isn't around the major scene either.
I think I pretty much summed up what happened.
I will say this though, Torres fights with Maeda and Mizugaki were awesome.