I think if Bitcoin was a stable price bitcoin would be dead right now. Because people invest in bitcoin because the value is not stable. They make money because of this and that is what people want. That is why everyone is here right now.
For starters Bitcoin is created as a currency in the first place and not as a mode of investment. Having a more stable price will of course be bad for profit takers or traders but on the consumer's end it will be good as businesses will now be more than willing to accept Bitcoin as a mode of payment because they know that the value of their earnings won't change or at least be near at what fiat currency has to offer. Bitcoin being a worldwide use currency will become a reality if that happens.