As a hater, I think it’s just a love of hating. Especially in a society where it’s acceptable (if not socially encouraged) to put-down other people. When people complain about scrunchies (or the USPS, or public transportation, or dorm food) they aren’t really attacking an entirety, they’re performing a dance of social acceptance seeking: “see, we are the same in our mutual contempt.” Should you reply “I love scrunchies” or “I’ve had great experiences with my mailpeople”, it tends to shock people into realizing they’re wasting their time on misplaced abuse. Or they’re just assholes.