I disagree. If they wanted to rob him, they could have taken his wallet while he was on the ground helpless, then run. There was no need to stomp him.
This strongly appears to have been an attack aimed at a random white male target, for the express purpose of causing serious injury.
Mindless random attacks against whites have been going on for some time. The MSM doesn't report on it. There's even a name they have for it... Someone here will know, I've forgotten...