For a long time, where were only really four types of beards – the full beard favoured by bikers and hippies, the David Brent-style goatee, the smaller Guy Fawkes combo and the soul patch beloved of jazzmen and, in later times, Mötley Crüe drummer Tommy Lee. Plenty of men only had moustaches with nothing on their chin, but other than Abraham Lincoln, very few had it the other way around. Facial hair was generally smart, the neat domain of policemen and sergeant majors, of J. Jonah Jameson and Commissioner Gordon.
There were outliers like Lemmy, with his glorious handlebar-and-chops, Metallica’s James Hetfield and his several experimental moustaches, and Black Sabbath’s policeman-like upper lips, but for the most part, metal used to be a place devoid of facial hair. Lars Ulrich had some disgusting bumfluff on his top lip for a while, and Slayer's Kerry King grew what he could, but there wasn’t a lot about.
Then, as the bands who would inspire nu-metal developed, beards started popping up here and there. Scott Ian of Anthrax, one of the first bands to combine rap and rock, sprouted frizzy gold dust from his face as early as the 1980s. Dimebag from Pantera had a pink goatee. Robb Flynn of Machine Head sported a three-pronged chin, Primus had had a few beatnik-type beards and both Mike Patton of Faith No More and Trent Reznor of Nine Inch Nails sported minimalist micro-beards in the 90s. So, by the time Korn rolled around, you bet your arse there were a few soul patches.