Sometimes you don't have much in common with members of your own "race". and if you're talking about people who date within their own race exclusively as a result of ethnic scarcity (to create a term), then obviously I've created a caveat... not ALL people who date only in their race are ignorant however it is an act of ignorance of some kind to ignore other partners simply based on their race
I agree with what you said about sometimes not having anything in common with people of your own race. I feel that way a lot.
But I don't believe that people who date exclusively in their race are acting out of ignorance. Not everyone who dates their own race is a racist or a bigot. Some people are just more physically attracted to their own kind. I don't see anything wrong with that. People have been dating people of their own race since like forever. I don't believe that you have to harbor some type of ignorance to be attracted to a woman or man who looks like you. Its actually the norm to date people of your own race.