This is a mischaracterization. 4chan was founded as a new place for Something Awful anime fans to post hentai and "loli" content after SA banned such things. It was always about contraband and bad-taste culture. The "dirtbag free speech" crowd flocked to it because of the side-effect of that initial culture being anti-moderation and being allowed to post whatever they wanted.
Can you see how '60s establishment types might think the same about people "hiding behind" peace and love gibberish to remain a cesspool of drug pushing, adulterous freeloaders, whose success in mainstreaming drugs and hostility to social institutions objectively coincided directly with an explosion in violent crime and social issues like single motherhood, drug addiction, rioting and urban decay, all of which rose to unprecedented levels from 1965-1975 in every Western country that experienced a similar "counterculture"?
That's not to make any judgement on the societal value of 4Chan vs. the 1960s counterculture. It's just that neither is/was a uniform group that can be defined as "rooted in X, Y, or Z," and people who claim they can are typically blind to the bias of their cultural perspective.
If only 4chan were rooted in those things. Sadly, it is rooted in only one thing: anonymised extremes. While you can stack other things on top of that, those are offshoots rather than the roots.
4 Chan is rooted in things that are objectively good: free thought, satire and not taking anything too seriously.