We already had viruses on DOS before CDs existed. The fact CDs supported autorun and Microsoft programmed Windows to have that feature on by default was mind-blowingly stupid and an obvious vector for viruses even at the time Windows 95 was new.
> We already had viruses on DOS before CDs existed.
But they weren't a credible threat that was significant enough to be worth worrying about.
We already have guns, but I don't do anything to protect myself against gun attack. It wouldn't be worth the time or effort or inconvenience for the level of threat. Maybe in thirty years we'll live in a dystopia and it'll be laughable that I went around unprotected against guns? But for today it's reasonable to ignore.
Probably legitimately wasn't at the time! The general landscape and security issues and reasonable concerns just weren't the same.
Of course it's as clearly insane as giving pregnant women beer in maternity wards now, but wasn't at the time.