Old school people could also prefer not to use addons...I don't except for my AVG plugin, and eye candy for strategus. And IE is pretty similar to any other web browser, but like someone already said, and I agree with, IE is more vulnerable to viruses, and I don't like how long it takes to load when I launch it. I don't like how long it takes to load a blank web page. The only time I use it is when I need to, for Microsoft branded web products such as CRM, Sharepoint, etc.
My wife still uses IE, and I still make fun of her for it, but at the end of the day, it's not going to make much difference what web browser you use (most people don't use addons as far as I'm concerned anyways).
But I do think it's funny, and very indicative of IE not being as competitive, or good of a product as other web browsers, when they are paying money to advertise on TV, to try and get people to use the web browser that comes installed on the operating system most of the end users' are using.