Well I'm not really sure if this is the type of answer you were hoping for but by any chance are you physically attractive?
That really tends to put a damper on negative feelings from others, no matter how you act out, their tolerance will be a thousand times higher than if the same behavior was displayed by someone who is harder on the eyes.
Simply a disgusting truth about humanity and I don't endorse it, but yea, could this possibly be something at play? (Unless you were referring to interactions on this site?) Maybe you don't display your anger as poorly as you think you do, or interact with people who are used to a dynamic where fights are frequent and forgiven...I know some families and friends can get away with that habit where others cannot, simply because it's what they're used to. The only other thing I can think of is if they somehow benefit from not engaging or reciprocating with their own anger, it's also possible they don't like your outbursts but keep their mouths shut about it for whatever reason.
I am a very bitter, miserable person and I also know I must either keep away from people, or find the energy to pose myself in a friendly (yet defensive) stance-which I hate, I do not like being "fake".
I have nothing that will temper anyone's reactions to my anger, so it's just another reason I isolate, and the more I suffer, the angrier I get. So I agree that usually people don't stick around when it comes to rage issues, or even the topic of an insufferable life. Perhaps, by some miracle, you surround yourself with compassionate people who let things slide because they know you are suffering..but that would be my last guess, knowing how human beings and society are in general.