How come just cause u like MCR ppl think u have a horrible taste in music?

like in questions about MCR ppl always say "listen to real music!"... im like wtf?... i love mcr but i also love iron maiden, nirvana, the beatles, the rolling stones, the foo fighters, skillet, and more... so yea, how come just cause someone likes MCR most ppl think they have no taste in music??