Former Minnesota Vikings and current Oakland Raiders punter Chris Kluwe wrote an article at Deadspin that was extremely critical of the Vikings organization suggesting that he was let go by the team for his outspoken activism. He does not go as far as saying that was the reason, but he thinks it was.
Kluwe is an extremely intelligent person and one who has never afraid to speak his mind, so it is not a surprise for him to speak out in this manner. The issue is that every single argument has a credible argument. People who want to believe what Kluwe is saying have plenty of evidence to support their argument. Those who think he was cut because he was a relatively mediocre punter have evidence to their viewpoint.
In the end, everyone can have an opinion on the matter and feel comfortable in their opinion. Kluwe was an outspoken punter and there could be NFL personnel who would not want that in their locker room, but he was also a run of the mill punter. This article would be far more piercing and devastating in its potential impact if Kluwe were regarded as one of the best punters in the league. Unfortunately, that is not the case, so people will just have to read what he said and decide where they come down on the issue.