You could use Linux if you wanted to, no one forces you to use Windows.

Also they own so much of the market because they don't have a competitor. Apple is a real niche player, so they're not much of a competitor.

A lot of people never had any problems with Vista, I can't say I'm one of them, but it being a terrible O/S wasn't experienced by everyone.

You consent to the data collection when you accept the End User License Agreement, so there's nothing shady about that.