I now recommend using Google Chrome Frame over actually making stuff that works correctly in IE. This just shows you the sorry state the IE is in. Microsoft is working on fixing IE with 9 and beyond but it just won't help all those people who don't really know what a browser is. However, asking for a plugin, and one from Google no less, will reach all audiences.
So the people at Google weren't insane, they just felt it was less work to fix IE than to break sites to comply with IE's view of the web. What I didn't understand at the time however, is that you can't just show a page when your user reach your site telling them to install another browser because too many people don't know what a browser is really. Also, in a corporate environment, they probably can't install one either even if they do.