Vista was innovative, but lacked (and lacks) the proper implementation. (The problems are mostly at the kernel level, which vaguely repeats the type of flaw seen in Windows ME). I used it for over a year and was always impressed by how fragile it is compared to XP and 7, so people got pissed off when their OS messed up on them for apparently no reason.
It's a terrible OS because it's full of bloat, DRM and crapware. It's also terrible because it's made by a patent-troll supporting, anti-competitive, free-speech hating corporation known as "microsoft".
This evil corporation, "microsoft", is trying to take over the world by bribing politicians, lobbying for draconian laws that oppress the freedom of computer users everywhere, and using patent troll companies as proxies to attack their competition unfairly, instead of competing with them on level terms.
Microsoft has never made any innovations, all it does is uses underhanded, criminal tactics to attempt to eliminate its competition, because its products are so bad it could never survive on a level playing field.
Fortunately, there are other options. Personally, I try to make ethical choices when I decide what to purchase, so I could never buy anything from microsoft, even if their products were the best in the world. Which they aren't.