[alan_cx]

Cars degraded over time, software does not. Get in a 10 year old car and it isnt as good as it was 10 years ago. Its loose and worn. Fire up 10 year old software and its as good as the day you bought it. Yeas the market would have changed around both, but if I have both a car and a piece of software in my hand, as it were, I can see the difference. There for leasing something the clearly degrades makes sense. Leasing something that does not degrade, does not.

[beat]

Software does indeed degrade over time - platform support (gee, do your Windows 3.1 apps run?), security flaws, etc.

[mikeash]

It's true for software that's completely standalone, a virtual island. But very little useful software qualifies. Most software interacts with other components, whether hardware, operating systems, external formats, etc., and when those change over time, the software effectively becomes worse, even though it's technically the same as it was before.