I'm very racist
Why are you racist?
I just don't get along with whites and blacks.
Being racist against black people, white people, or any other people is terrible because it treats people differently based on something that they have no control over. You should judge people based on their personality and actions, not their skin color.
Grindr enabled black people to stay away from me.
It's okay if you are not physically attracted to certain races on dating sites, but that doesn't mean that you should judge the entire race.  All people are individuals, and should be judged as individuals.  The fact that someone's skin is a certain color will not affect how well you get along with them, unless you want it to.