I agree that people, generally, are rude.
But, what I think the op was trying to describe is that bad feeling I get when I see another cyclist do something rude, illegal, etc. Because I am a member of that group, it makes me feel like I am going to be judged or compared to the cyclist who is being rude. While i do get mad other drivers, it's not the same feeling; I think it has to do with being a member of a "minority" group, that others always are not so keen on. The best thing I can compare it to is the way I feel when another Jewish person is accused of a crime or something immoral. It's like his/her actions speak for the whole group.
Perhaps not everyone who rides gets this "feeling," when observing other cyclists behaving badly, but I know that my DH and several of my riding friends do
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