I have to say I sadly agree with some of your points regarding value, purchasing ability and market penetration. All these issues are showing a big fail in Bitcoin development over the last year, which I've been preaching about. The unregulated free for all anti-fiat currency of the future has merely become a financial platform for big fiat fishes. Most of the development has shifted towards that focus, ignoring usability and every day commerce.
I think, however, you're wrong in your conclusion. Even if what you say happens and 99% of the people leave when/if we go below 50, that's REBIRTH, not death. The people left will then be in charge of steering the project back on track, hopefully in the right direction this time, but it may even take several tries of this whole process. If Bitcoin goes into a slumber, there's a reason for it, and it needs to be corrected. The fundamental values of the original concept will always be valid and valuable, up until the day there is a stronger crypto-currency or alt-money to compete with fiat.
And that's the bottom line, the demand for Bitcoin (outside of speculation), is in reality the demand for an (unregulated) alternative for gov' controlled fiat. As long as there is no bigger player in this segment, Bitcoin cannot die.
You know, this is a totally valid view point. Some sources suggest that literally 100's of millions of people around the globe have at least heard of Bitcoin. Maybe the $100+ prices were just to high for the masses to run to, but at $20 or $30, maybe that's a point where more people would jump on board. I don't claim to have a crystal ball. It is all speculation. But I do try to evaluate my investment as I would in any other business and as it stands now, the long term viability of Bitcoin is shaky iMO, given it's lack of market penetration and it's pure speculative nature.
My words are not an attack on crypto or even Bitcoin. It's just an individual perspective from a small investor. I have continued to call out many of the short comings of Bitcoin for quite awhile now, and those have not changed. In fact, the more time that passes and the BTC community is still begging for Dropbox or some other non-major company to accept Bitcoins, while the publicly traded companies continue to snub Bitcoin, the less I believe in the viability of Bitcoin. Again, just my perspective and that's part of how I make my trading decisions. No one should take that personal. This is just business.