Just think of all that Carbon used in migrating...
Lotus 123 and WordPerfect to Excel and Word respectively.
I'm sure someone can come up with a metric for the number of times if/then/else code is executed on an average website which determines whether or not to render it in an IE compatible format. The amount of code, cost of code maintenance, speed of access, the number of visits per day where such a metric would apply.
Biting the hand that feeds IT
