It’s been a long, sad story that the Powers That Be generally didn’t give a rat’s ass about any other browser than Internet Explorer on Windows. If they were enlightened, they might say “make it work in ‘both browsers'”, which meant Netscape 4.0 (which was such a crappy and divergent browser that you are better off not worrying about it).
Times have changed. The combined efforts of FireFox, Opera, Apple, Google, and mobile devices mean that you can’t just target IE/Win any more; you have to consider all user agents. This quote sums it up nicely:
Things are easier now that we no longer have to appeal to companies to be “better Web citizens,” which was like asking Nestle to promote fruit as a healthy alternative. Now we simply point out that over 90 million people don’t use Internet Explorer, and some of them just might have money to spend on your services.
From Interview with Firefox Founder and Creator Blake Ros, via Cafe con Leche.
It’s the “money” that’s the key here. PTB’s typically won’t listen to “this is better for all of us in the long run” but they will listen to “you’ll lose money directly if you do this”.
The irony of this is that making your site IE-only is typically more difficult than it is to make it standards-compliant. It’s quite easy to make a site that is workable (although not necessarily visually perfect) in all major browsers. The reason many sites intentionally lock out non IE/Windows users is that they want their site to perfectly match what the Graphic Designers cooked up for them in Photoshop. A lot of times, you can’t do that without resorting to IE-only hacks. If you show them how bad it looks in any other browser, at best you’ll get “we don’t care”, and at worst you’ll get “then let’s block them from seeing it”. Either way, you’ll get “they’re only 0.1% of the market, they don’t matter.”
Until now, that is.