More to the point, why not just make it work in every browser? I realize we're not supposed to mention this here in the land of 60% FireFox and 35% Chrome, but

More to the point, why not just make it work in every browser? I realize we're not supposed to mention this here in the land of 60% FireFox and 35% Chrome, but most of the world still uses Internet Explorer as their daily browser. If you want to make a product that people use, you have to make it usable by them. And that means developing for IE first and your browser of choice second.