I've done the Dallas CM ride a couple times. It's not as big as HOU by any means and the vibe is very chill / low key. Yes they stop traffic, but OTOH every weekend shopride / hammerfest around here also blows through stop signs and red lights so I don't see a whole lot of moral high ground for the roadie crowd there.
In general my view is that most of us are habitually in a hurry for no good reason and it doesn't hurt you much to take a breather once in a while. It's no different than if you get caught waiting for a train at a crossing that's usually empty. Just chill.