That's a good point. Though I'd say at least part of that was nationalism. I think today's racists are a bit more desensitized to Olympic diversity since it has been the norm for so long (which it hadn't been back then). The people I know that think like this understand that some people are better at some things and that naturally breeds diversity, but they'll use that as an excuse. For example they let it reinforce an "all brawn no brains" stereotype of certain ethnicities. Whereas I think Hitler wanted to believe or push the idea of complete superiority in all aspects of one race.

But it's not just that one example, they will find any amount of reasons and excuses to accept the current reality while also accepting their anti-diverse beliefs. And they'll believe there is no contradiction. At least, a lot of them will.