Well it might not be possible for a decentralized crypto currency to have a non-fluctuating value; at least at the beginning. Since it is decentralized it cannot be declared "worth something" by fiat; and therefore needs to garner its value organically. It makes sense you want to stay away, but bitcoin is still super early stages and growing.. if ti plataeus or at least becomes more or less predictable over time due to "finding its price" then those with your concerns will be more apt to adopt.

This isn't really a flaw of bitcoin but rather of markets/people.

Once bitcoin gets near some sort of saturation point in terms of adoption, you are likely to see a much more stable valuation. Now though, it's the wild west and its neigh impossible to separate the speculation from the fundamentals.

I will say though that I don't see wild fluctuations in bitcoins price as a flaw in bitcoin. I see it as inevitable for any currency bootstrapping itself from nothing to something. The path from zero to any valuation is bound to riddled with crazy swings as people get hopeful and then scared.

Consider: if bitcoin had instead had demurrage or increasing rates of inflation, how much less likely would the early adopters have stayed around? It's all well and good to consider ideals, but creating a tradeable, limited commodity out of thin air that people actually want is no small task and it has not been proven that there is another way to do it. If there is no incentive to be an early adopter, there is no reason to take the risk; you might as well just wait until it is widely accepted to start accepting inflato-coin; but with the possibility of dizzying-gains there is a strong incentive for people to use bitcoin before it is proven (which is only slightly less true today than 2 years ago); and this incentive is -- while not part of the technical appeal of bitcoin --inseparable from its success.