Reasonable enough in some way. But you say “racist website.” That would be a very broad allegation. You then get to upbraid OP for a proclivity to “impulsively alleged racism whenever …”
Do some people demonstrate the failings you point to? Sure.
Does OP, or would OP? I have little idea.
I won’t assert that the point is true, but if OP noticed something about 51% of posts her opining on the performance of Black runners, took that perception, and then at least roughly weighed that against the performance of runners, then, OP might feel secure enough in advancing an opinion about a particular runner.
In that hypothetical, does that make this a “racist website”? Nope. Would OP then suggest that this is a “racist website”? I highly doubt it.
So that would also be a likely weak investigation for OP. But I’d still consider it far likelier that OP would find a racist individual than that anyone could find evidence of this being a racist site.
And then imagine more posts following. And an onlooker trying to determine the motives of each poster.
Do we necessarily land on an end point of a poster being unbelievably racist?
Nope.
It would be a weird and highly unusual situation for us to find circumstances that would enable us to call this a “racist site” (within reason).
But I’ll also say that it’s not at all unlikely that in a given year 1-2 posters will say something racist. And probably many more posters.
But very few are affiliated with the ball club. And fewer still speak in a way that we could construe as representing the views of the ball club.
So I hope you’d do research and be very confident before levelling accusations of very unseemly activity before anyone who might appear to be innocient .