People are afraid of depressive traits, specially when it's not something they're accustomed to nor know how to deal with. They let their impulses to flourish instead of anything else. They remember their own suffering and assume it's comparable to yours (comparing suffering is quite the idiotic thing to do) and that you're not putting on your side for dealing with life's harshness.

I mostly gave up on explaining anything when I find myself being judged by strangers on negative ways, I can't blame a person for not knowing how to deal with a complex situation they were never been in the need to face. Though sometimes I may start playing with people when they got judgy with me when I occasionally show subtle depression traits, because I feel like having nothing to lose.