There's a video doing the rounds titled "how to write a hardcore punk riff" (see below). I never learned much music theory, other than what my high school bass teacher imparted to me regarding basic major and minor scales and the structure of blues-rock. So the video was interesting, as 12tone breaks down some of the patterns behind hardcore punk-rock.
Let's start with something 12tone nailed: "It's really easy to make boring punk music." So true! It was easy to identify the greats back in the 1980s, some of whom the narrator cites - Bad Brains, Minor Threat, and the Dead Kennedys. We found out about these bands through word of mouth, live shows, fanzines, listening to records at friends' places, or college radio.
But boy, was it hard to write songs as good as them. I realize why. It's not just a question of getting the theory wrong. In our zeal to reject everything about "classic rock," and the 80s electronic influences that were taking over the pop charts, we were listening to too much punk and hardcore. It wasn't until Feiwu (1997-1999) that I really began to consider other influences, including Taiwanese nakashi music.
It's very clear that the most creative and impactful musicians and artists are usually the ones who are doing things differently, not blindly adhering to the "rules" for whatever came before.
All of those seminal hardcore bands not only had fantastically skilled musicians (including vocals), but also they were coming from a much different place than we assumed, something I didn't find out until later. It's a mistake to think of them as amateurs who only knew the Sex Pistols and Ramones before they picked up their instruments.
Bad Brains started out as a jazz/pop band. Greg Ginn of Black Flag also had a jazz backgroud. I read somewhere that one of Black Flag's favorite albums in the tour van in the early 80s was ZZ Top's Eliminator - Texas blues rock meets synth drums.
Flea, who played bass in Fear before cofounding RHCP, was a high-level trumpet and French Horn player in high school, and grew up listening to his stepfather's jazz influences. East Bay Ray of the DKs - surf and jazz. D Boon of the Minutemen studied flamenco guitar at one point, which you can hear on Double Nickels on the Dime.
There's a great book by Michael Azzerad (Our Band Could Be Your Life) which gets into the influences of many 80s/early 90s bands including Minor Threat, who late in their existence were veering off into U2 influenced rock.