If you've ever bought a consumer Windows PC from the bottom end of the market - one of the cheaper machines that are engineered to an incredibly low price point and usually shipped from a known brand OEM - you'll have experienced how bad Windows can be.
A combination of bloatware and poor drivers doesn't do Windows any favours. My own recent experience with a cheap HP laptop would have put me off Windows for life, but for the fact that I knew this wasn't a representative experience.
On the right hardware and without the OEM garbage Windows offers a great user experience. You just need to be careful about who you're buying your Windows machine from.
Maybe the time has come for Microsoft to offer a certification process for PCs, one that guarantees a certain level of quality experience for end users. It would certainly go a long way to removing the stigma that Windows has (unfairly) picked up.
As someone who uses OS X, Ubuntu and Windows 8.1 on a daily basis I'm entirely happy to recommend Windows to my friends and family - but only on the right machine.