I personally don't hate Windows, but I do dislike it compared to UNIX type operating systems. It was only recently that Microsoft even bothered to incorporate some of the better, mature and time tested UNIX ideas, and they botched them or they are marginalized by the sheer inertia of existing code written and being used that was authored at a time when the OS was significantly less capable.
Right now, I'm really not feeling good about the Windows 8 moves. A lot of leverage is being applied to get people to adopt Windows 8 because that's good for Microsoft, but it's not necessarily and arguably not good for said adopters.
Microsoft depends on license revenue and in particular renewal for a very large portion of their revenue and this impacts choices people have and those choices are sometimes quite expensive for no real technical purpose, only to make money. Lots of people don't like that, because it's artificial value as opposed to real value.
UNIX set the bar for computing before Windows even matured to the point of being able to run moderate applications. That's not changed, and often things are added to Windows and or changed to either exclude UNIX, or bastardize the ideas in ways that make cross-platform code more difficult than it could be to author. Overall, this is easily characterized as "shitty" in that people end up with false computing choices and or doing work or spending money they would not otherwise do, if the OS were actually designed to function as an OS, not some sales platform.
Finally, application dependencies make life difficult for everybody, even Windows users in that those limit computing choice for the purpose of maximizing revenue at Microsoft, but that comes at farily high external costs to everybody else in the computing eco-system. This self-serving behavior, coupled with the increasingly dubious licensing terms and conditions just isn't a value add, and is growing to be a burden.
I dislike these things, because I would much rather purpose my time getting things done rather than deal with false choices and expensive licenses / funky terms. The messy application / administration space is just extra foul icing on top of a shit cake.