the price manipulation is hardly the biggest issue with bitcoin. manipulation will not stop regardless of mass adoption (in fact, it may increase as users increase).the biggest issue with it is real use cases that benefit the average consumer, of which there are none.

a lot of commodities are 'manipulated'. there are always big players who understand the market well, and you can bet your ass they'll use their strength to their advantage. don't fall into the overly conspiracist camp and just take in the world as it is. manipulation is just part of the market.