Back in the iOS 1.0 days, the iPhone development platform was web apps. These were pushed by Apple as the "right way", which negated the need for an App Store. As the browser engine on iOS is basically identical to the desktop WebKit, I always assumed Safari for Windows was a push to enable iOS development on Windows.

With the release and success of the App Store, that became unnecessary. I guess killing it was a function of its relative lack of popularity; Apple in the Jobs 2.0+ era justifiably don't like keeping dead-weight projects around.

I always found it odd how Apple didn't follow windows user interface guidelines on Windows, forcing the Appleness on Windows. Weirdly, they don't follow their guidelines on Mac OS either, unless the crazy window design of iTunes is meant to be normal?

Just speculating, but probably Safari on Windows was a strategic play, to try to increase the adoption of WebKit and lessen the death-grip IE had on the internet then (and to encourage/give an easy way for web devs to target+test on more than just IE).

Much different landscape now. Most devs are running macs now anyway, Chrome exists and is very popular, etc.