Edd Bot's article is very old, and the problem was mostly resolved with SP1. You no longer get reduced functionality. Microsoft also state that you should have no worries if your copy is genuine. I have found this to be correct. As a business man, I would certainly examine any possibilities that existed to protect the product which, hopefully, was about to make me very rich..
Referring to the car analogy. If you study the OS Eula, you will see that you do not purchase the OS, only the right to use it ad infinitum. If you leased a car and tinkered with the engine big time,, you would be in similar trouble.
Right or wrong, Microsoft pride themselves on having a very sophisticated, working system. If computer users are unhappy with the price, something I would fully understand, there are alternatives, from free and upwards.