That is actually "the point" that many people are missing. Bitcoin can only succeed or expand its user base when people "invest" in it. If people "invest" in it, they expect higher prices. If they expect higher prices, they will eventually try to get out and take their profits. That cycle is the source of Bitcoin's volatility.
But Bitcoin was originally meant to be not an investment but a currency. A currency is not an investment. A currency must be stable and have the "unit of account" function.
On my first Bitcoin meetup, an university professor (economist) from my home town threw in the following statement: "If we could launch Bitcoin on a new planet and base all our commerce on it, then it could work". Implicitly that means: Now that we integrate it into the actual economy, where people only "are in for the profits", it won't work. Because people will use it for speculation and not really as a currency.
I think he was a bit pessimistic, but I think also that the Bitcoin community should do more for a more stable price. That would not mean that "investors" could not profit. That's why some posts ago I made the proposal to divide Bitcoin in "shares" and "currency" (it won't be easy, but perhaps with the upcoming PeerAssets it will be possible).