Yep. Everyone has a stake in people being decent to people. Some people's stakes are higher in certain situations than others. I was called "lesbian" as a slur in high school, but my stakes in lesbians getting treated as human isn't as great as it is for actual lesbians. But that doesn't mean I don't have any stake in it.

And even people who never get -ist slurs thrown at them personally (do they exist?) have a stake in society being a better place, if they have any empathy at all.