Bitcoin is mainly adopted for its volatility and not for liquidity.When bitcoin price starts remaining stable means, that bitcoin is adopted by people in a wide range, so that no one can affect its price by pumping and dumping.Traders can gain profits only if bitcoin price is not stable and is volatile.They benefit by trading it against US dollars.I think, if bitcoin price remains stable, it would be dumped for price to fall..If bitcoin had a stable price, then its adoption would fall.
Though it is not possible to have stable price of BTC because of the economics behind it (Mining) just like Gold but I disagree with you concerning adoption, what Bitcoin offers is more than price, the anonymous nature makes it a darling currency for Dark market, this is where BTC derived most of its market price (Monero a recent example), the low transaction cost gives it edge in the remittance market, even Forex exchange, now I can buy things directly with BTC from China and USA, before what I would be concerned about is how to source for Forex. No matter the price, Bitcoin will always serve some niche of people.