You're right, and you probably could have posted it as yourself to get the credit for it.
I think it's entirely related to social skills, not knowledge or capability. It's not limited to intelligent people, nor skilled people, nor nerds. Here are some real-life samples from other areas of life... and these are based upon personal observations I've made, they are not made up.
Out in the country: "I just got this Ford truck and it's awesome!" followed by "Ford sucks! You should have bought a Chevy, I bet that thing falls apart next month!"
Some iPhone users: "Ugh, I can't believe Instagram would sell out and go on Android, now I have to look at what POOR PEOPLE are eating!"
Gun owners: "You bought WHAT little pea shooter? What a girly little excuse for a gun. Lemme show you what you should have bought..."
Downtown: "West side for life!" "East side!" "West side! Thug life!" "CRIPS!" "BLOODS FOREVER!" *gunshots* *dead people and broken homes and families*
Cats & dogs: "Dogs are SO much better than cats. I don't know what anyone would own a cat." "Well cats have X attributes and Y whatever else" "Yeah well they're still stupid and so are you for liking them."
Mac vs PC: "I don't know why you'd want a PC, they are so complicated and buggy. People who like them are nerds and they need to stop being nerds and switch to Mac." "Might as well get a Playskool My First Computer then, in fact get someone else to use it for you, because you obviously can't handle technology."
Red Sox vs Yankees: "Yankees suck!" "27 championship rings say they don't, where are yours? Why do you like things I don't like?! You're a moron!"
Certain trolls and their counter-trolls: "XYZ solution! Use it and worship my goodness! I have credentials! Anyone who disagrees with me is obviously wrong and wants a fight!" "No way, get outta here! You're a jerk! Why do people still pay any attention to you? Everyone block this guy!"
Religious trolls: "$deity said this, so you're never going to have any hope and should just die!" "Well @deities are stupid and you're stupid for believing in them!"
I could go on forever. Nobody would have called ALL of these people nerds, but they all have the same problem. I could go on, but you're still 100% right on about it being a social skill-related issue. It just extends outward to all populations! It's just not something they teach in school, or on TV, or anywhere really... parents need to do this and if the kids are left to themselves to be raised by people on the Internet, well... you know what happens. They learn to be like those people. Kids are taught in school to have safe activities and not injure each other physically, but not really to respect each others' opinions... so everyone just wants to be right all the time and they want recognition that they're right, who cares about anyone else.
Random passers-by, can you see the problems here?