It’s invalidating, dismissive and not even factually correct to make a global statement that anger is a secondary emotion and assume that there are “real” feelings underneath someone’s anger simply because one is feeling angry. Maybe you want my anger to be a secondary emotion, so you can move on to the “real” feeling underneath it and not deal with any discomfort my anger might cause you, but that’s called “I’m uncomfortable,” not “anger is categorically a secondary emotion.” You can’t ask how something makes you feel and also tell people that no one can make people feel anything.