They're actually correct that putting <Person> on the $20 dollar bill, though deserved for her contribution to American history, does nothing to fix the system or eradicate racism. It's just another empty gesture to keep black people complacent and make us think that things are changing. Nothing is changing, but the powers that be will sometimes come out with something (like playing the Black National Anthem at football games) to simultaneously pacify black people and turn us into scapegoats for racist white people who wait for something else to complain about and run around with their "white people are the real victims" narratives. 

The funny thing is, it's almost never a black person behind these sorts of things but because there's either a black face or just the word "black" attached to it, we're suddenly to blame. 

Sorry for the little rant. I just needed to get that off my chest.