Microsoft lied and said that Windows wouldn’t work without IE, to justify bundling it with Windows after they signed a decent decree with the US government forbidding them from using their natural monopoly in operating systems as leverage in other markets.

WebKit is used by several Apple apps—Mail, iTunes, App Store, Calendar, etc—and thousands of 3rd party apps.

But the problem is not to stop them from shipping webkit with ios, but to allow other browsers to use their own engines. Do you imagine what would happened if every browser on Windows had to use trident for rendering?

Microsoft ended up with 'n' version of xp, which had all shortcuts to IE hidden, and a prompt asking you which browser you want to install and use after installation.

That was during windows XP wasn't it? I'm sure things have changed since those times.