I don't think BTC price volatility is the primary cause for not using it. But based on my knowledge as of now bitcoins are not accepted by many governments because they can't track the transactions and can't put taxes on to it so many businesses are not taking it as a payment method. Currently, bitcoins are used mostly in online gambling and for some limited online activities.
Price volatility is the main reason why there are additional person uses bitcoin. Because of the price volatility in bitcoin, we have the opportunity to earn big.
The only institution that don't like the price volatility of bitcoin are those companies/merchants since they are here for business. Also if that merchants are dealing with dollars, it will be hard for them to face the risk of accepting bitcoin as mode of payment.
The last month bitcoin price has stabled. I hope it will stay thst way or increase slowly without bubble building.
Without the big volatility it would attract even mor merchants!