I'll take a stab at explaining it, although it's probably more complicated than this.
There are people in the world who have very little power in their lives, very little to point to as an accomplishment or a good thing, yet they crave that sort of attention and good feeling that comes with such things. Hence they instead play a comparisons game:
At Ieast I'm not:
- A person of color
- A person with Down's Syndrome
- Out of shape
- An ex-con
These people love having a feeling of superiority, but they don't get it from being faster or stronger, smarter or kinder, or from having talent or an education or a good way with people. They get it from this sort of superficial garbage. And if they don't feel superior enough, then they actively try to put the other person down.
Hell, I've even seen it in the weight loss community, where people look down on anyone who's had plastic surgery, or took a weight loss supplement at any time, or who has/had more than 100 pounds to lose (by the way, I've been all three).
I suppose you could refer to it as toxic snobbery.