Although not a witness myself, and I can't speak for any, but I believe the symbolism is not lost on the witnesses, nor is it meant as a racist attack.

Rather, it is a protest meant to convey that the witnesses see the path taken by the Tron in using misappropriated customers funds to centralize the network (most likely a bunch of sock puppets running on a single node) as a sort of death of legitimate Steem governance. Apparently the core Steem developers and communications director agreed, as they resigned over it.

Hopefully it is a 'death' from which Steem can recover. We shall see.

Either way I would not overly fixate on the symbolism. The message of disapproval and protest being conveyed is more important.