The reason the world of IT is different to the car or other electronics industries is that you're dealing with an abstract product, a product which can greatly enhance your existing hard ware potentially, without the need for anything new.

The problem how ever is that you can't just keep an 'old' OS because companies like Microsoft force you into upgrading. Eventually all support gets cut, updates don't come, other companies software ceases to offer support, and your existing OS is artificially out dated by money hungry organisations.

It's not just about having the latest for the sake of it, in a fast paced industry like IT things are improving, security features and the like are often added as we learn and improve. (Although I do admit this isn't always the case!)