You guys seem to have an inability to think things through. Personally, I don't much go for symbolism one way or the other. It's a cheap way to score points, whether you decide to sit or stand.
However, if anything, the money he makes is the last thing that should be held against him if you choose to hold something against him. He purportedly chose not to stand not for himself but rather for his black brethren who have less of a voice. And he did so at some personal risk, again assuming the story and his rationale are indeed as presented. That makes his act rather selfless, by definition.
So while your collective sensibilities may have been offended, which is your right, you ought to try and make sure that your reason for feeling all that extra, over-the-top outrage is a coherent one.