Or, alternately, we'd all be griping about still having to use Python 1.x until people stopped using IE. It's only been the last year or so that you could start thinking about sufficiently large percentages of your users to be running current browsers.
That has a pretty simple answer, it's because it was the only language available in the browser (and no, Java applets never really took off).
Had it been Ruby (unlikely given the timeline) or Python or even Perl instead, the situation would probably be much better today.