It's not really Windows 8 people hate, it's Metro. Under the hood there are some very good improvements, but nothing on this earth would induce me into using Metro. It's an ugly, awkward to use, counter-intuitive mess because putting it simply, it is designed as something to work well on phones and tablets and to be just about tolerable on a desktop.
You just have to realise Microsoft's dilemma: the consumer is increasingly moving towards using toys because most consumers are not power users. They spend most of their time surfing, playing around with pictures, music or movies and that sort of stuff. Outside of business hardly anyone is a power user - if they were they would find a tablet woefully inadequate.
So Microsoft is increasingly seeing their traditional core base, where everyone used a desktop type (even a portable one, ie a laptop) shrinking in favour of one where they have virtually no existance rapidly expanding.
They wanted to move into this new area but at the same time can't abandon their core because desktops are still very important, espescially in businsses. So their solution was Windows 8, which unfortunately ende dup being a jack-of-all-trades but master of none. It's never going to challenge iOS or Android because it;s far too late and Apple and Google have the market completely stitched up between them, but at the same time it it managed to piss off an area where it is still very strong because it foisted a touch and small screen friendly front end on users that have large non-touch screens and many of which have little interest in things like constantly updating Twitter or weather tiles beyond finding out how to turn the damn things off.
If Microsoft had included a full Windows 7 style front end as well as Metro and allowed people to choose, this could all have been avoided. But that would have saddled them with just what they wanted to avoid, ie having to support two front ends, one for desktops and one for mobile devices.
I think that very few people would have selected Metro on a desktop if they could have kept all of the other Windows 8 improvements but kept the Windows 7 operating style.
Just my take on it anyway.