Honestly, I believe that the Web would have been better had we stuck to those expectations more diligently and evolved more slowly and thoughtfully. That one can does not imply that one should.
Blue links and purple visited links were fine. And now on most sites there is no differentiation, and it’s sometimes difficult to tell what is a link, and a lot of sites don’t even bother linking. This is not an improvement!
Blue and purple links wouldn't be visible on any website that chose to use those as background colors (or any range of background colors where the contrast would have been too low to be visible).
The web at the time was an "anything goes" multimedia format, not a dry digital paperback or textbook where all the content had to fit within the publisher's specifications to limit printing, weight and distribution costs.
Nowadays, most browsers have a "reading mode" that can flatten the content into something that satisfies those Nielsen conditions though.
> any range of background colors
Backgrounds should only be #808080
I don't disagree with the opinion, but what individual experts think does not factor in much when you have a groundswell of adoption like the web did. At that point people are going to hack whatever they can on top of it, and there are too many varied interests to have any central control, and so things just evolve well beyond the intent or control of any individual mind or architect.
For me, usability mattered a lot and I saw how a lot of the web design experimentation was falling short, but Nielsen was just too backwards looking. We needed forward thinking UX rooted specifically in web culture, and that's what we got through the Zeldmans, Veens, and 37signals of the era.
> Blue links and purple visited links were fine.
Red when active