I don't think that is human instinct, it's the attitude of arrogant humans. But not all humans are arrogant so your statement is overbroad.
It really depends on what you're talking about, and how attached you are to it. Like I can talk about phones all day long and not get too bothered by it. I like my iPhone, generally prefer iDevices, but I can see the appeal in Androids. If someone buys one, I'm not gonna get angry about it, and assume they only did it because they're poor, uninformed, or whatever. Specially if they buy a phone that's roughly the same price as mine.
It's a stupid thing to get worked up over.
But we get into a conversation about something like cake vs. pie? Yeah. Someone's gonna get hurt.
cake eaters are freaks