Are you sure (see http://www.forbes.com/sites/timothylee/2013/04/11/an-illustr...) plenty of examples. Maybe not over 24 hours, but certainly over short time periods.
I agree volitile isn't worthless. But it limits the mass adoption I have about 3BTC and I saw them be worth $600 and now $300. Had I been an ordinary 'risk averse' person, and I paid $600 for them I'd be pretty cheesed off (aka pissed).
>> Also, no currency has any intrinsic worth anymore.
Yes! This can be generalized to "nothing has ever had, has, or will have any intrinsic worth", which I agree with. A dead cow is worth more than a bar of gold on a desert island, but vice-versa in the 'normal world'.
>> The biggest difference with bitcoins is that nobody can create them out of thin air due to whim like they can with USD.
Yes BTC is more like Gold in that respect, although ironically the intended use case is a currency not an investment. Fiat currencies are the best confidence trick. Even if you know you are being conned, you still have to play along!
I've never really understood the objection that people have with regards to the Fed printing USD (for instance). It's actually a pretty powerful regulatory tool, isn't it? A small amount of inflation is fine (I think the Fed targets about 2%), but high inflation or deflation is a problem for people who have savings in USD. One way to manage inflation is to control the amount of dollars in circulation, which can be controlled by printing or not printing new dollars (and removing old ones from circulation). There are other ways, but the Fed is fairly limited in terms of techniques it can apply. Can someone explain why bitcoin advocates so often object to that control?
Maybe this will happen. Who knows.
Bitcoins/Altcoin "mining" creates coins out of thin air (+ silicon and electricity).
Yes, but not at a whim; that's the important distinction. The precise creation schedule for all bitcoins ever is known in advance (and Bitcoin creation is slowing, and eventually will stop). This is distinct from any fiat currency, where the minting authority can arbitrarily decide to inflate all your cash holdings out of existence. This has happened many times throughout history. See the German Papiermark.
Also, no currency has any intrinsic worth anymore. Currencies are all a consensual mass hallucination. I still think it's feasible that if enough of us agree that bitcoins are worth something, then they are worth something.
The biggest difference with bitcoins is that nobody can create them out of thin air due to whim like they can with USD.