would be explicitly liking someone based entirely on their race, and nothing else

That's definitely a thing: fetishizing people because of their race or some other characteristic. I know some weebs, for example, who get deep into that groove. I also have known people who have a kink about having Black sexual partners. And I know two Black women who each like to date white guys and do roleplay with them that involves racial abuse. Both are upper middle class and highly educated. I find all of those fetishes weird, reductive and creepy. But maybe that's just me. Others might draw their lines elsewhere.

I also know couples where the partners are from very different ethnicities, and they're not all weird about it. For example, I didn't get with my wife because of her ethnicity, it was about her intelligence, character and (OK, I'll admit it) strikingly good looks. I knew nothing about her culture at the time.

I was responding under the assumption that the statement about reverse racism was saying that it's impossible for people to be racist against white people.

The rest of the world understands that racism towards any person is wrong.

They understand that it's just called racism, but it's not universally seen as wrong. There are a lot of countries with significant racial prejudice, besides the US. Thinking it just doesn't exist elsewhere is naive.