All bitcoins will be found by 2033 I believe and if there isn't enough transaction fees by then to pay the electicity people will just switch off their computers.
It is a pyramid scheme in the sense that the supply of coins is being limited and so they become rarer over time.
This doesn't enable stable prices and will hinder shop take-up of bitcoins because anyone holding stock is losing value on it all the time bitcoin is gaining value.
Quick note; all BTC will be found sometime in 21xx; you forgot, the reward gets cut in half every so often
