I'm inclined to agree with the last three posters. People buy consoles so they don't have to think about specs and minimum requirements, and figure out how to upgrade hardware. If modular upgrades were sensible, then other console manufacturers would probably be doing them already instead of releasing entire SKUs that are essentially "Console 1.5" or "New Console Pro X".
The fastest way to scare away the masses is to make anyone other than the hardcore/enthusiasts have to do more work (both with their brains and their hands) to get to the fun. The fastest way to scare away developers is to make them have to do more work (both with their business decisions and their programming) to figure out how to put out games to as many as possible as efficiently as possible.