And only somewhat true for punk. Once you're a mediocre guitarist, you finger the whole chord in case you strum too far.
Dream Theater would be the prime Example. The three founding members studied at Berklee.
Metal is probably one of the most technically and music theory driven genres. It attracts people who really want to get GOOD.
Somewhat true for punk, mostly incorrect for metal. A lot of metal is very analytical, deeper in musical theory than most popular genres (rock, pop, rnb…), they care _a lot_ about it. Metal is often very technical, it bred some of the top musicians in the world, it’s no surprise they give a shit about it: it’s their craft and a hard one.
In fact I remember the singer of Gojira in a French interview, saying (iirc, surely not quite remembering his point) that metal is in many ways closer to classical than rock, as it values composition so much more where rock is all about interpretation (closer to punk)