If only he were brave like Sherdog posters; lets face it, anyone can get into the cage with top level UFC fighters, but true courage lies in posting on Internet forums.
The really funny thing is that no matter when a fighter retires, there's always some courageous Internet poster ready to say they slinked or ran or otherwise proved themselves a coward. Rocky Marciano quit because he was afraid. Same for Ali, Tyson, Frazier, Foreman, Couture, Liddell, Lennox, Klitchko and everyone else (seriously, search and you'll find someone saying it for all of them, and everyone else who retires).
This is why Sherdog is so much fun, you have the incredible spectacle of Internet people who've never stepped into the cage at UFC levels (or any level) calling guys who have cowards. You just can't make this stuff up.
GSP is clearly an opportunist, saw easy money in Bisping and took it. Thinking that's cowardice ignores the years of fighting the top guys that it took to get to the point where he was given the fight (which he absolutely hadn't earned - he hadn't been in the cage in four years, and never fought at MW, but was given a title fight????). But I blame the UFC for giving him the fight, not him for taking it. We all accept free lottery wins if we get them.
Now people are saying Woodley is a coward for wanting the money in fighting Nate (an easy fight) instead of less money fighting a WW contender. What part of earning your living do people not understand?