depends on what you regard as a useful state Windows is perfectly fine for the avg person like me. Same as IE, it gets tons of shit but ive never had a problem with it because it does really just what i want it to which is browse websites. had to ditch it and get chrome as crpg website stopped working on IE O.o People who are into computers or programming etc will always moan about stuff like windows but you have to remember its just not made for you, Its made for people to use office and do random crap ^^
You can't do office with Windows. You have to buy/pirate and install MS Office or download and install OpenOffice or something similar. The only reason why people are content with Windows is because it comes pre-installed. But nowadays you can have that with Linux distributions, too, from many computer vendors. And then you can simply plug it in and do random crap like you can do on Windows.
No, there are only two reasons that can sometimes be used against Linux, and they are a) driver issues (sucks when hardware vendors don't provide drivers for Linux and some home programmer has to make his own) and b) gaming. The latter point might become less important in the future due to Valve's efforts. Which could later reduce the gravity of the first point as well.