This is not just an NFL thing, it happens in all team sports....if a really good player is on a team that is not winning, they bitch and moan because the team is not doing enough to get better....they are essentially saying, "replace my teammates with better players so we can win"....they act like the most important thing is helping the team get better and they are applauded for wanting to win....as soon as an organization decides that they are a potential target for replacement, all in the name of getting better, they freak out like its the biggest insult they could receive....in a culture where winning is placed on a plateau and revered above all else, how can a guy not see that no one is untouchable, no matter how good of a player they are? It's simple mind-bottling, you know, like when all your thoughts are bottled up....
you like getting handjobs? yes you like giving handjobs? no hypocrisy at its best. no one likes to be in the middle of the circle jerk, so when its your turn, you kinda expect a little bitching about it.
It's a lack of awareness, more than anything. Most professional athletes (especially ones who are currently, or have once been, at the top tier) are unable to recognize that their weaknesses are hurting the team. A trade is usually a very forceful reminder of that fact, and most of the time they react nonsensically towards it.