“these genres are for the musically illiterate”
How incredibly bigoted of you! Most lead guitarists in metal bands could teach college level classes in music theory, some on the level of Stratavarius.
In order to play with that kind of speed and precision, you need to understand how and why certain paterns and teqhniques are applicable. To call them genres for the musically illiterate is just as wrong as me saying that every Jewish musician with songs on mostlymusic is a hack that just stole lyrics from Dovid HaMelech.