Can we kill this bogey once and for all, assuming you're referring to the change of lens mount.
Canon changed the lens mount from the old breech lock system to the present one - because they had no choice. They knew AF and the rest of the electronics was coming, and there was nowhere on the existing lens mount to fit the contacts needed. It's true they peed a lot of people off, but it was totally unavoidable if Canon wanted to incorporate the impending technology.
On the other hand, while it's great that you can still fit any old lens to a Nikon camera, the fact is there was sufficient room on the face of the lens mount to take the elecrical contacts needed, and it was sheer good luck for Nikon and for their customers - nothing more - that they didn't have to change the mount.