You're wrong freebutcaged, everyone can run their own node, if you design the software as smart as can be.
And it's the best way: a not-central bank (where are you getting the idea that everyone running their own node is just 1 big central bank

)
Doing what you're suggesting (miners are the only full nodes) gives too much power to the miners to change the Bitcoin software to whatever they like, that's a part of what all this Bitmain controversy is all about. And re: downloading only part of the blockchain, that's been in Bitcoin Core since version 11, since over 18 months ago
Why then on many Bitcoin forms some users agitate others in order to create Bitcoin Bank. Really it will be Another scam in the field of crypto currency, although I apologize maybe I did not fully understand what is being said.