I don't think it is as much "disposable" as it is economics, sourcing, lead times, etc. The result is definitely "one off". Our company used to buy a brand of laptop that had at least 6 versions of the same model number. Outwardly, they were the same but internally, the components were different and not interchangeable. Very frustrating when you are trying to repair them or replace parts. I just think they use whatever they can purchase at a moment in time be it a better price, availability, etc.
Brendan