If they are being oppressed, then why do they have the freedom to take a knee? A few bad apples should not be the cause for senseless behavior.
If you listened to Tommy's remarks before MRI took the stage, he spoke about how they all know how relatively privileged they are just to be playing football in such a spotlight. He said that MRI -- as well as every other athlete who has done so really -- is speaking for others.
Everyone has the freedom, I suppose, to take a knee somewhere. Don't mistake that basic right for actual equality.
All the ways in which people do feel injustice continues unabated and even unrecognized today, I don't think it's imagined. Much of it is demonstrably not so. Look at the report on Ferguson, for example. Wouldn't you be mad, too, if that were your own community? Wouldn't you want awareness and change? Wouldn't you settle down for nothing less?