Till now, bitcoin seems the perfect currency in in the free world, it has many advantages as we can see. Such as convienence, decentralization, no worry of inflation, except for the boring blockchain file lay in system partition.
But to me, I think I treated it as gold as many others did, so maybe we will hardly to use them, just holding to see price up, obviously it will cause the deflation, and then the bitcoin will not be currency any more, but like treasure.
But it is not treasure, and let's consider this situation, one day, bitcoin has been granted, and suddenly a big catastrophe attacks somewhere in the world, and destroyes all, people die, bitcoins of those people then lose forever, so the price up, others will hold their bitcoins more tightly, and no bitcoins are in the circulation.
No curculation, so it can be called curreny?
The only true point why deflation was chosen as a feature of Bitcoin is to make early adopters (and Satoshi) rich. If Bitcoin succeeds in the future it will be just a side effect. Unfortunately, probability of such event is very low. So deflation will rather be fatal.