This opinion/fluff piece has a whole host of problems aside from the one picked out by the OP. In a nutshell, the author accepts commodified diversity as a social good. For her, the growing number of non-elite sponsored runners and the commercialization of road racing is a positive trend because it has gone hand-in-hand with the diversification of road races. Previously, "skinny white dudes" got all of the money and glory; now, whoever successfully brands their running lifestyle can also get sponsorship. Nevermind the fact that running is a place where skinny dudes strive for athletic excellence and showcase the aweseomeness of the human body. Conveniently, she leaves out the many sponsored non-white men and women who excel in road racing, many of whom do not get paid very much for their hard work.
The commodified diversity mindset allows her to dismiss complaints about charity runners at Boston without considering how the corporatization of road racing has simultaneously attracted a more diverse running population (arguably a good thing) while turning what used to be cheap community events into bourgeois vacation attractions with exorbitant entry fees. As long as we have equal access to self-branding and consumption, we're on the right track.
A few caveats: I get that running fanship is good for the sport, financially, and I've always liked the participatory nature of road racing. In what other context can a hobbyist compete against an Olympian? I think we should consider why running is overwhelmingly white. Is it preference? Availability of role models? Access to safe streets on which to run? But I am offended at the suggstion that prioritizing athletic excellence, whether that's via sponsorship or road racing entries, should take a backseat to corporate diversity initiatives.