They did not however, prevent you from downloading and installing netscape like Apple is currently doing with iOS.
I believe that was Nadella's main point, which I don't disagree with.
While they did attempt to embrace, extend, extinguish, the platform was fundamentally not locked down which still allowed the web to take over.
They absolutely tried to, and were only stopped because the Justice Department told them that bundling IE with Windows was an illegal use of monopoly power. It's interesting that Nadella gives Microsoft credit for that and not Attorney General Janet Reno, under whose authority the Justice Department pursued the anti-trust case against Microsoft that led to browser bundling being declared anticompetitive.
I don't know about netscape, but I currently use a browser other than Safari as my default browser. Unless you mean the underlying framework is WebKit?
Apple gets complete control over what a webpage can do, and chooses the features it supports to ensure the web cannot compete with the app store
The funny thing about that phrase is that it was invented to describe Active Directory's relationship with LDAP and Kerberos. Active Directory is definitely one of Windows's killer applications, and rather than attempting to kill it, Microsoft instead makes a killing off of it.