You've missed the point that using the analogy of "biker gang" is inherently portraying groups of people that ride on motorcycles and have a favorite bar are inherently bad people. Biker gangs have often been portrayed in the media in a very stereotypical manner that has little bases in reality. How would it sound if I used the analogy of a "gang of black thugs with their baggy pants and shitty music" moved into my community and ruined it, and that "they should get high and make our white women uncomfortable elsewhere"? Same thing.
Look at your own comment of "go deal meth elsewhere." Is the irony lost on you?
Even past that, the analogy is flawed because it assumes an organized group of "bad people" that move into "my space". There is no such organized group, and it is no one person's space.
Even past that, there is no group of people on Reddit that "show up and destroy or dominate the entire conversation." I've been on Reddit actively for about seven years and while I definitely see the vitriolic individuals (and some specific toxic subreddits), I think it is incredibly childish to suggest that "my safe space is ruined by all these bad people!" The site has not been "dominated" by "the bad people". It feels ridiculous to have to say that about a place that gets, what, 7+ billion pageviews a month now?
Come on.