Some people like the ability to compile a fully customized operating system that only runs the processes they want to run, doesn't phone home every few days or hours to make sure the OS that's installed hasn't been altered in any way, that doesn't need an anti-virus, anti-malware and constant maintenance to keep running, that doesn't constantly remind you of things you already know. Some people like the ability to change the every feature on the desktop, or have several different desktops at once, all different, running from a single machine. Almost everything the average user wants a computer for can be accomplished in linux running booted into memory from a 1GB flash drive.. even a computer that has no working HDD. To be honest, windows 7 is a great operating system, but it isn't so freakin great that all other operating systems should be eliminated. And if there are no games available for Linux, it's only because there's no money in developing them.
Computer wise, limiting yourself to a single operating system is just as ignorant as only learning to speak a single language.
Some people, by that you mean a few geeks run Linux, all that rubbish about phoning home, and not needing AV etc, you know as well as I do why it isn't necessary, its a thing thats not worth the hackers time because so few people use it.
There are even more Macs than Linux and they only have a small share of the market, be honest if Linux was so good it would be up there alongside Windows competing for a bigger market share, people aren't stupid or ignorant to know whats good, and what isn't,
Your comment about one system and one language shows your own foolishness, I reckon the majority of the worlds peoples only speak one language, and have no wish to learn another and you reckon thats ignorance, and all the people that use one system are ignorant as well,
You find a good system and stick to it till something better comes along,
I wonder why you have more than one system its tells me you aren't sure what you want, me I've seen all the others and decided this is the best,
and that is the only criterion, no ifs, no buts.
Oh and if you wonder about the Vista, thats purely for the oddments that don't run on Seven, and that is down to the manufacturers who won't upgrade to Seven.
Anyway Vista is nearly as good as Seven but not quite.