Tearing into a popular piece of media is just really, really cathartic, and much more so if a group of people agrees with you. And if we're gonna be honest its punching up most of the time, so it seems fairly harmless. Someone brought up Nickelback, its not like they've been shoved aside from relevancy, they were super popular the entire time people tore up their music critically. If someone puts them on at karaoke (or if someone puts on Starship for that matter) I'm sure most of the place is going to sing along.