[bell-cot]

Sure, there's an endless salad bar (the article's phrase) of nasty ideas and ideologies online.

But is the online talk a meaningful cause of real-world bad stuff, or a symptom or side-effect?

I'd say that Accelerationism was (in effect) a real-world thing for over century before the ~1970 thinking that Wikipedia cites as its background. Just look at the staggering social and technological upheavals from 1850 to 1950. At the start, a sail-powered wooden warship, capable of 10-ish MPH and using gunpowder to fire small balls of iron, was still pretty much state of the art for a major nation projecting military power. At the end, that state of the art was intercontinental bombers dropping atomic warheads.

And no techno-capitalist ideology was needed to force those changes. Nations which wanted to be (or stay) on the world's A List had to change, invent, and industrialize as fast as they could, just to keep up. Nations which couldn't, or didn't, faded into obscurity.