He has time-trialed a few fast 5,000s and picked up a bronze at a WC.
Besides that (which is quite an accomplishment, but not because he's white)... his popularity rests, it seems, on his ability to use words like "balls" and "f***" in interviews.
How big were Mottram's balls the week before when he lost significantly to Webb, whose mile PR is only .06 faster?
How big were his balls when a post-injury Ritz kicked his ass a couple of weeks before that?
It's just a bunch of talk. I'm personally looking forward to the next time (which I doubt will be too long from now) when he gets toasted by some white guy and all of the overblown junior-high talk will be turned around on him by the fickle letsrun junior-high crowd.