The IE integration with Windows was to extinguish Netscape Navigator. So I'm guessing this move is probably to destroy chrome and indirectly google search.

Microsoft used their OS monopoly to destroy Netscape. Not sure if it will work today since they don't dominate the smartphone space.

Or, maybe, document/file search is a pretty useful and commonly expected feature for a desktop operating system? And extending it to online search is an entirely natural next step?

Even if this were a plot against Google, it would simply be bog-standard competition. It has absolutely none of the characteristics of "Embrace, Extend, Extinguish".

I can't believe you'd suggest something as rediculous as users wanting a unified search bar that just gives them what they want regardless of context. History has shown time and time again that users like diversity and would prefer a solution that they can tailor together in a piecemeal fashion after trying all their options.

This is some high grade sarcasm!

i don't believe you describe the average computer user.

> What are they embracing so they can extinguish in this instance?

Firefox, linux, open source. It's really funny how a lot of open source projects are hosted in github.