Maybe in your opinion vista has saved your more time, but for others they prefer to not be tied into Microsoft products or really don't like paying the retail cost of Microsoft products.
You mention you have worked on DOS MAC OSX, Unix, XP and Vista, however you don't mention linux. A modern version of linux (my choice is opensuse 10.3 however I also use xandros and busybox) and in my opinion after having used opensuse 10.3 I can never see myself going back to Microsoft in the foreseeable future. The reason being, it does everything I need. The KDE desktop is very powerful, Compiz Fusion, the 3D desktop is Amazing and very stable. It provides a stunning music player "Amarok" when used with the xine engine. Firefox & Opera for web browsing, It has an office suite, word processor, spreadsheet, database, Impress presentation, it runs skype, it runs Amsn so I can connect to up many chat networks. Xine and mplayer's capabilities exceed that of windows media player, but that's the tip of the iceberg. Opensuse and I would imagine all the other major linux distributions come with in excess of 1000 applications. Once you start making a little effort and reading about linux capabilities you will feel like you have just walked into Aladdin's cave. Another reason for using linux is that I don't feel Microsoft give me value for money, in fact I feel totally ripped off, especially when Microsoft report yet another profitable quarter. I don't believe they deserve it.
It's true that 9 out of 10 computers run MS windows but that's because the majority of hardware resellers are payed to promote MS windows by Microsoft and the majority of users don't know they have options that are often more functional and almost always at zero cost in terms of hard cash. The problem for widespread adoption of linux in the public sector is that Microsoft discount windows & office to such an extend that, for instance if you are an NHS employee you can get a legal copy of office for about £17 ( whilst employed by the NHS ), that you can use at home. Great for NHS employee's, no good for anybody else.
Dell selling linux on their systems is a total joke. I've never seen a company work so hard to not upset Microsoft. You just know Dell have either been slapped by Microsoft or Microsoft have made them an offer they just cannot refuse, so there promotion of linux is virtually non existent.
Somehow I don't believe you have made much effort to understand linux or the many free and open source applications that are available, it's worth the effort !
A few of the computer's I have programmed with ...
Data General, DEC (RT11), Perkin Elmer Mini computers, MSDOS, WINDOWS 3.11, 95, 98, XP, linux all either in assembly language, C or C++. Linux (opensuse-KDE) is by far the most stable, feature complete OS I have ever used and no I have not used Vista, other people I know have bought it on new systems then reinstalled XP. So I think I'll stick with linux. Thanks.
Computers in the house 11, 8 running linux, 1 running XP, 1 running win2K, 1 running solaris.
Computers at work ~150, 102 running solaris (unix), 10 vxworks, 30 DOS !, 4 XP, 4 linux.
Linux FanBoy and proud of it :)