This is the term for all vaguely leftwing causes to get conflated, such that trying to talk about any one of them usually ends up in a rabbit warren of sub-discussions about everything else.
This caricature is not entirely undeserved. Plenty of people can shoehorn Palestine into every single discussion.
I still don't understand what the comment means.
The internet is indeed very good at squandering young people’s passion and energy, directing them towards endless debates about the right sub‑sub‑ideology in blogs and subreddits with 1,000 subscribers, rather than towards actually changing people’s lives.