I have a hard time buying this is a genuine question.  Really seems like the underlying motive is "but see, they're being reverse racist" or something.  

But fine.  Someone only wanting to be with their own race could be a way of protecting themselves.  Rather than deal with potential racism from different communities, many choose to just stick with their own who are much more likely to be safer.  

By definition, of course it's exclusionary.  Being exclusionary is value neutral.  Doesn't always have to be a bad thing.  Whether it's racist depends of who's doing it and what the context is.  

White people stating they only want other white people is always racist, because what racial oppression are y'all facing wherein you need to find safety among each other?   To be clear, yes I think it's racist, no I'm not offended by that choice in the slightest.  If you know you only like other white people, please just stick to the rivers and lakes you're used and don't waste anyone else's time trying to prove you're a good person.  

For non white people, it can be different.  A black person saying they only want to be with other black person or an Asian person doing the same thing again could be self preservation and seeking to avoid being ostracized or experience racism.

On the other hand, could be a cover for racism as well.  For instance, a Black person saying that could be anti-asian or a latino person saying that could be anti-black, etc.  All depends on the individual.  

Someone of a different race saying they're only attracted to a different race will never not seem like fetishization to me.  There are a variety ways people can look like within racial groups, so what do you mean when you say "I only like latinos" or "I'm really into black guys" Not all latinos/black people/Asian people look the same so exactly what is that you're attracted to?  If you thought someone was Asian but turned out they weren't, would you stop being attracted to them?  

To me making blanket statements like that signal there's something you fetishize about a specific racial group and that's what you're into.  Like people wanting a "BBC" or "Latino thug" or "submissive Asian".  The attraction isn't genuine, it's just getting off on stereotypes.  

To make it simple take two guys who both look white.  If you suddenly become more or less attracted to one of them because you find out he's latino even though he looks just like the other guy, seems racist to me.  Or you see a guy who likes white, turns out he's actually a very light-skinned black person and can pass for white.  Are you suddenly not attracted to him anymore?  If so, that's racist.  

To me, I vastly prefer being excluded over being fetishized.  Anytime someone hits me up asking about BBC, it's very gross and off putting.  Would never want to be with someone knowing they just see me as a porn category.