hmmm smells like BS
Real web developers write sites for IE whereas Comp Sci students who are doing some free work for their uncle 'designing' a web site tend to go overboard on the standards compliance, it's that simple.
What total and utter unremitting bollocks - damn - I just bit a troll.
If you go by the way in which a browser renders a page rather than by the name of that browser, IE doesn't really have market share.
IE 6 and 7 render differently so that's 2 different categories.
Opera 8+, FF2+, Konqueror and Safari render basically the same. On some sites this could quite easily get something like 25% IE 6, 35% IE 7, 39% stuff that's W3C compliant (give or take) and 1% other... meaning "IE" is not dominant.
It gets better - in most instances IE7 actually renders more like Firefox or Opera than it does IE6 - look at padding in the box model for instance - so unless you're accessing the JS DOM you could say that IE7, Firefox, Opera and so on all render approximately the same. Even giving IE6 the generous market share of 30% it's still a minority browser these days - any web developer working in the "real world" will only worry about it as a secondary consideration.
IE7 only really becomes an issue when coding web2.0 shinies using the JS DOM - and you can get around those problems by using a JS wrapper "class" and providing noscript alternatives.
The whole point of coding to W3C standards is that if YOU follow the standard, every browser on every operating system following the same standard will display your code the same - even those you've not tested. I've not tested my work site with Safari on OSX (as I don't have access to a Mac) but I've been informed it works fine with my standards compliant code (oki - I put an onresize in the body tag that's not compliant).