Bad actors would do bad shit there due to the very nature of the site. Probably, the misfits could have found some other, healthier, place to congregate. But they didn't, and so 4chan was important, to many people.

It's a shame it got weaponized by bad actors. There was once a day when such attempts would be met with "4chan is not your personal army." Unfortunately, the bad actors got smart enough to figure out how to turn them into an army anyway.

Beyond that, I believe it's important for social / cultural / political structures I disagree with to exist in small "gardens," left to their own devices - both as a living example of "yup, x or y doesn't work, go to 4chan to see what it results in," but also because sometimes it does work, and it's important to keep those traditions alive.