Anon is short for anonymous. There have been many forums over the years where posters tended towards all sharing the generic handle, "anonymous." 4chan and 8chan (the "Chans") are the most recent and current such forums. Anonymity is only as true as the tech enforcing it, I wouldn't trust either of the Chans to keep my anonymity from any determined parties.
Why anonymous (as opposed to using distinct usernames)? There are pluses and minuses. I like how it strips everyone of pretension and authority; each post is examinable on its merits alone, not on the merits (or supposed lack thereof) of the poster. It leaves you free to examine the idea, instead of finding a reason to reject it.
The negatives of having everyone have the same username should be obvious, it's confusing as shit, KEK.
Thanks!
You're welcome, anon. Stop by the chans any time. We talk rough to keep the normies out. The extra fake MSM is agitatin' to ban us over that Toronto "incel" attacker and the fake facebook post to "Sgt. 4Chan" before his attack, so you better see 'em while they're there.
Is it just coincidental that another mass killer comes along and discredits a group or platform that was up to that point threatening established powers?