Because it would be doubly depressing if they not only had better gear and were also better musicians. Being nice people would make it the hater trifecta.
Letting the wares and accomplishments of others be a personal yardstick is a sad way to go through life. As an adult, do I get jealous when I see someone with "better" or more expensive gear than mine? Nope. Do I hope they can't play? Of course not. And fortunately I didn't think that way as a child either. It completely misses the point of being a musician.
LOL, yes indeed.
I'd imagine that while at a guitar shop someone gave you the evil eye when you whipped out a boutique bass of some sort and/or someone started to try to out-shred you. Insecurity isn't hard to spot.