Alot of that is also large enterprises that wont upgrade. Where my brother works, the mindset is that you dont need to browse the web at work so there is no need for a "modern" browser.
Until an approved program uses the built in HTML renderer for a news page or help file or something, and calls out to the web and gets the whole system compromised within minutes.
Very easy to happen.
Windows lets programs do whatever they want. Just because you don't actively use them doesn't mean they aren't used by other programs.
(This is also why Linux server admins like to pull every single command and program out of their machine that they don't absolutely need.)
