>>While the "does not wear out" part is mostly true (SMB2...), most people would feel decidedly unsafe driving cars from several car generations ago, missing ESP, exhaust cleaning, LED or at least halogen lights for starters. That car generations take longer than software ones you probably will agree with - thnk dog years at least. That some people need automatic gear shift, electric windows or a navigation system before even thinking of entering a car might be a comparison more relevant: think automatic backup, SOAP integration and so on for the software side

Cars do wear out and it can be difficult to retrofit new features such as an automatic gearbox: but that's not true of a 4GL unless people decide to prevent change. IOW I'm saying that a 4GL should not be perceived like a motor vehicle where you really do have to start over to achieve many new features.