Ruminating on the 'death' of Windows XP

Yesterday I read that Microsoft has extended the cutoff date for sales of Windows XP, again. I've seen countless articles discussing this, read a few, and had coworkers discuss the topic with me. The consensus seems to be that this is evidence of the failure of Windows Vista.

This has me wondering why Microsoft (or really, any publisher) needs to kill old versions of software at all.

Ever since I was a teenager I wished car companies could continue producing certain classics, even years later. I'd love it if it was possible to still buy a 1976 Delta 88 convertible, or a 240Z, or a first-generation RX-7, new. But as recent events show, car manufacturers incur large expenses, and it would be untenably costly for them to produce extra models. It would also run afoul of various safety regulations, certainly - a 1976 automobile won't meet 2009 auto safety regulations.

Software is different. There aren't any safety regulations concerning Windows. And the cost of producing and reproducing the software is inconsequential.

I'd think Microsoft could simply produce any version of any software they've ever produced and sold, and keep them all avaialble pretty much eternally. If for some reason a person wants to buy a copy of DOS 5, where's the harm in that? If somebody sees a compelling reason to want Vista, they can buy it and install it in place of XP, Ubuntu, or whatever they had previously.

If a person or company wanted to use XP, they still could. If Microsoft felt that XP was no longer competitive in the marketplace, they could produce a newer OS, such as Vista, to comepete with the other OSes available. If Vista, Windows 7, or whatever else bested the competing systems, then MS would make money from it. If people decided to NOT buy the newer system, they could either buy XP, or something from a different publisher. In that case, Microsoft still has a shot at collecting money.

Instead, we have a situation where Microsoft will ONLY offer Vista, and if a buyer doesn't like that, they need to either try to find some 'sneaky' way to procure XP, or legitimately buy some other OS from somebody other than Microsoft. Microsoft also has to deal with the PR and marketing hurdles in their way as they try to extend the sales-life of XP without looking like Vista was a failure.

I don't see the sense in this. If Microsoft instead sold anything they've ever sold, to anyone at anytime, they wouldn't be in this situation. I don't see a downside.

Of course, I'm not a sales/marketing person, and my brain simply doesn't work the way theirs do. Men are from Mars, Women are from Venus, and Sales/Mktg are from some planet in the Alpha Centauri system.