Because without good conditioning you can't train your skills hard. Without good conditioning your strength is useless because you quickly lose the ability to use your strength. Without good conditioning you lose your ability to apply your skills.
Using your logic, if someone doesn't have a fight or competition comming up why would you train strength?
Or hell, why would you train skills? I mean, can't all three of these things be picked up like a month before a fight? Or is it just conditioning that you can just suddenly build up?
Anderson silva obviously has very good genetics. He also pays (or has sponsers who pay) for top level strength coaches to over-see his form and general program on a day to day basis. He also has other specialists making sure he gets the right nutrition, supplements, rest, recovery, medical care etc etc etc to help him continue at the top level.
Also, he doesn't have another day job that he has to worry about.
"over-react with fatigue levels"-
Both Irish and I have had partial shoulder dislocations at least partly due to "fatigue levels". I myself have suffered from half a dozen of so partials, and one full dislocation over a year and a half.
I was only benching 3x5, 3 times a fortnight. My form was pretty solid, as solid as it could get without expensive, professional tuition. But scince dropping bench from my program I no longer suffer from chronic rotator cuff "fatigue" (read- "pain and loss of movement") and have had no further dislocations.
I'm sorry that I over-react when my shoulder is flopping around out of it's socket. I'm sorry if all I have is non-conclusive evidence to suggest that benching was making my shoulders hurt (i.e. I bench, my shoulders hurt, I stop benching, my shoulder stops hurting) and that my experiences have made me paranoid about benching.
And I said, sure, the bench can be a part of a fighters program, and good luck to those who use it. It's can be used to good effect to build high levels of upper body strength. How applicable this strength is to real life is under debate.
My point was that for many people it is not the best option . I think KMC's point was that it's not the most useful or appropriate upper body strength exercise considering that the guy is a grappler.
I am failing to see your point, other than "if some ufc guy can do it, you must be a pussy/scared/paranoid/have bad form if you can't"
Which isn't a point that you've made well.