Let us not assume beforehand that Bitcoin is a ponzi scheme, neither that it will be the future currency. From other axioms I believe it is the latter:

As long as BTC rises drastically in value, people will hoard.
Let me call ambient rise in value the rise in value of humon society (all food, technology, music,... society finds better ways to do things everyday, society grows).
As long as there are enough newcomers to the "ponzi scheme" (some actually believe it is and consciously enter it realizing they are among the first, let me call these ponzi newcomers), the value will keep rising, however the difference between a future trader and a ponzi newcomer is not a thin line. At some point in time, the specular rise in value will diminish and start fluctuating about the ambient rise. Now that segment of BTC holders that were pure ponzi investors will get out of the game decreasing its value somewhat. It is a public secret that if a BTC bank run happens, your BTC could end up worthless. Why would a trader sell his BTC for nothing? At this point you have non ponzi mindset investors still owning BTC. But remember as the specular rise fell away, only an ambient rise is present (that a-rise from average real world work), so hoarding is no longer an issue, and trading WILL commence.

Your argument mathematically equates the claim that value is not a continuous function over time. This is true and false, it is true in that a specific trade of BTC vs USD has a spread as we all know. But there are average values, and these are most certainly continuous.

What you say amounts to: BTC value as a continuous function, is now rising (positive slope), and will -WITHOUT flat 0 slope- start falling (negative slope). The crucial magic of BTC trade will happen once the value starts stabilizing.

The ponzi mindset investors, (who do not actually value the crypto nature of the currency, but societies interest in it) will "step out"/keep their BTC in the new trade system that will really only materialize when nearly all ponzi mindset newcomers feel left out in the cold.

The unfair distribution feeling is a necessary part of BTC that tells your ponzi side of your (sub)consciousness that you wont be making money out of thin air after all.

You could claim that these feelings have been posted on the boards for a long time now, but still the value of BTC is rising like crazy. This just means that there still is a considerable part of newcomers who believe they can ponzi their way with Bitcoin. *some* day old news for some will also be old news for most.