Up until recently, I had an old computer at home which could only run NN4, IE5, and iCab. NN4 was the closest to the functionality I wanted, so that’s what I used. If I couldn’t use it on a site, I normally never went back to that site (which would of course, if others did so as well, lead to lower numbers).
Now that I have a newer computer, I’m on Mozilla 1.6. People who use older browsers may not have a choice (my case) or may now know how to download a new browser. And the few who are on MSNTV (formerly WebTV) don’t have a choice.
Anyway, there is a difference between catering to NN4 (what we have done in the past), being NN4 tolerant (what we will be doing with the next technical redesign of our site)and NN4 hostile (which we won’t do because we’re a public agency and try not to annoy people).
Back to the article itself:
As for duplicating browser features, the average user is not familiar with those features. We’ve gotten multiple complaints about people not being able to zoom PDF maps we’ve published; zooming is a built-in feature of Acrobat Reader. If it’s not out in front of them on the Web page, they often won’t know it’s there.