I think old distinction between the words "unsociable" meaning not wanting to socialise, and "anti-social" meaning causing trouble to society, is useful. I guess I'm swimming against the tide with this one though
https://en.wikipedia.org/wiki/Anti-social_behaviour
"Asocial" means being non-social. "Anti-social" means being a problem to society. It's terrible terminology to be sure, but those are the current definitions, and it's surprising that no one in the chain of publication for this article flagged that.
It's a fairly common pattern in English: e.g. "moral - amoral - immoral", or "political - apolitical - anti-political".
> it's surprising that no one in the chain of publication for this article flagged that.
I think the choice here is deliberate: the century stands accused of being hostile to social life, ergo it is anti-social, not asocial.