The curious thing about the word "slave" is that it originates from "slavs" i.e. people living in slavic countries, who were forced to slavery, yet we aren't freaking about that (I'm a slav by myself), it's just a word.
It's the way our brains work - the intention doesn't necessarily matter. Next time you're pissed off, try expressing out loud how "darn peeved" you are and watch how much words change how we think and feel