What Are You? A Communist?

A couple of days ago, I was introduced to the friend of a friend. This was totally social, so I was just being my normal, potentially obnoxious self. Okay, not reallly, but I DO sometimes like to be a bit edgey when I meet new folks in social situations. This was no exception!
Upon our intro, the friend of my friend blurted out, "I don't like your dog!" To which I replied, "Good thing he's my dog and not yours then, eh?" Said person follows it up about how she used to like dogs, but then she got bit and now she's afraid of all dogs. I kinda sorta get this, but I still asked, "You don't like dogs? What are you? A Communist?" Why? Because I don't trust people who don't like dogs. I can understand being wary of strange dogs from events in one's past, but to just flat out not like dogs? Yeah, I don't trust those people.
So, as I thought about this, I was thinking about the ways I've been hurt in the past. My sight was taken by a 29 year old white male. Do I therefore steer clear of 29 year old caucasian men? No. Mainly because this woulda been pretty hard three years back when I -WAS- a 29 year old white male. And then there's that girl who broke my heart when I was a freshman in high school. Due to the emotional torment, do I now steer away from women? Hmm, why don't we ask my fiance? And then there was the businessman who bilked me out of several thousand dollars when I was just beginning my speaking career. Do I stay away from businessmen in the industry due to that one dude? Hardly since, well, I AM a businessman in the speakers' world.
Again, if someone has a traumatic experience in the past, I can understand being wary of letting oneself get hurt again. But to categorize anything, anyone, any dog...well, it ranks right up there with communism: good in theory, bad in practice.