4chan is perfectly aware of its reputation, and if that wasn't enough, it's worth noting they banded with kiwifarms on this one:

https://www.bbc.com/news/articles/clyjq40vjl7o

>Lawyers representing controversial online forums 4chan and Kiwi Farms have filed a legal case against the UK Online Safety Act enforcer, Ofcom.

Drumming up public support is a no-go. Rather, I think the intent is to make the stance that if the UK wants to prevent citizens from accessing sites if they are underage, then the UK can do just that, rather than expect random companies around the world to comply.