Perhaps your rudeness conceals powerlessness. When something can't be changed, when the situation is spinning out of control, and society still expects you to act, it's easier to put on a mask of irritation. Being angry is at least some kind of action, a release of energy that somehow masks the feeling of impossibility.
Sometimes rudeness is an attempt to distance oneself. From other people's demands, from the need to discuss feelings, from one's own vulnerability, which is frightening. It's much safer to push someone away with thorns than to risk showing that you care and potentially hurt them.
It can also be an inability to communicate differently. Many of us have heard since childhood: "don't cry," "don't whine," "be a man." We were taught to act, not to talk about our experiences. And when resentment, pain, or confusion hit, the vocabulary for these states is simply absent. All that remains is an instinctive, almost animalistic reaction: growling to warn of danger.
I don't regret rudeness. I regret the cause.
I'm not advocating justifying rudeness. But I'm also advocating, first and foremost, that we look deeper. Ask not, "Why are you so rude?" but, "What's upset you so much?" Give them space, don't demand an immediate "correct" expression of emotion.
Because behind a man's rudeness often lives the same boy who was once not allowed to be afraid or sad. And even as an adult, he still doesn't know how to express it differently. Perhaps our job isn't to snap back, but to gently help them find other words?