Black Flag was one of those bands you had to see live, in my opinion, after "Damaged." It was about letting the rock back into punk, a real dangerous energy as well, and beyond those horrible "loud fast rules" songs most bands were trying to make a hardcore career by

So long as you actually saw them live during this period and aren't just saying something you've heard repeated a billion times before, I'll take your word on it. I've seen a couple bands live that were pretty good live, and obviously biting off Black Flag's ideas in huge gulps, though their records suck, so that makes sense on a theoretical level.

As for bringing the rock back to punk rock, I dunno. They were doing that, but, really, were fighting off a trend that Black Flag itself was largely, though not solely, responsible for helping get off the ground. I don't really like hardcore, so I know this is coloring my judgement, but that's still a negative net gain for punk, if that makes any sense.