It's so grotesquely unfair that these guys are only playing these small clubs and a plethora of talentless hacks are dominating the larger club/arena circuit. Absolutely absurd. If only people valued musicianship when they saw it.
It takes time, because periphery is a difficult band to digest, even for people who are used to this type of music.
People who listen only to things like generic metalcore need to to "practice" their own taste in music. Aesthetics perception is subjective, but it evolves too. If someone likes metal, some day they are going be appreciative and feel for polyrhythmic music and complex progressive metal/music.