In a hypothetical situation, if satoshi ever comes back, does he has the power to kill crypotcurrency?
YES.
Let's say he comes back and says
"Okay guys, we're upgrading to Bitcoin 2.0.
This new digital currency has worked out all the bugs found in Bitcoin and is infinitely more efficient and has all these new features not seen in currency before.
Time to upgrade!"
Then everyone will switch over.
DUHHHHHHHHHHH
By your reasoning , if Bill Gates launches a new operating system , you really think everybody will switch to "Doors 8"?
More likely people will start arguing about the new features and about why he had come back and promote this.
Lots will see cia and nsa involvement with his re appearance.
YES. If Bill Gates comes back and says
"Okay look guys I just came up with the ultimate operating system ever made
EVER
It is 99999999x better than Linux and Mac OS X Combined
It is 999999% fully customizeable
Plus no matter what computer you install it on, even on a VHS, it will be faster than the fastest supercomputer today"
Then YES everyone will switch to that DUH
Too bad we can't have a bet on this.
You give both Bill Gates and Satoshi way too much power.
There are lots of example in the past of failed attempts to reinvent.