It’s like when I tell someone in my group not to use the r-word then it’s like I personally killed their family with the looks I get. Or not to use the slur for schizophrenic people. Just get this weird “…okay” in a deadpan tone. Sorry I am such a joykill to not tolerate this kind of crap, I know I used to as well but learned that it’s unacceptable but I hoped those close to me would be able to try and change too… 
They refuse to admit language they use could be construed as hurtful or hateful to others.
It’s also hard when it’s words that appear normalized by society