Or maybe the reason is that Apple has 'standardized' on the MagSafe for power and their implementation of their ThunderBolt port.
What actually gets me is that Apple hasn't extended the MagSafe concept to other connectors for the entire line. I'd like to see them come up with a MagSafe USB adapter and a MagSafe ThunderBolt adapter. MagSafe audio too.
Think of the docking possibilities if the whole left side of the MacBook Pro, for example, was MagSafed. Slip it in, pop it out. I know of a few people with PeeCee notebooks who have fractured their USB ports, and broken thumb drives, by having their notebook on their lap/bed/airplane/hotel. I myself have had issues with my MacBook Pro being almost pulled off a table by a marauding dog sharking the kitchen table when they trip over the cables and the power pops off and the ethernet, or USB, nearly drags it to the floor and certain heartache...
MagSafe is, IMO, an industry changing technology. Sticking things into notebooks is bad enough. Having them lock in just invites sadness and tears.
It's time for Apple to 'Think Different' and ditch the snap-in plugs! Free your notebook! Declare independence from old technology! Start a new market for companies to make adapters! I think it would work...