Does anyone anywhere track the growth of retail establishments, whether on-line or brick and mortar, accepting Bitcoins? I would assume that the longevity of Bitcoin would depend on it's eventual fulfillment as a utility to make common, everyday purchases.
I agree with your assumption, and I doubt that rise in bitcoin value matches the increase in goods and services which you can buy for btc. A lot of people are buying bitcoins now just to sell them for fiat in the future. And they will begin to sell soon, because there is nothing else to do with them. And this is when bitcoin value will fall back to adequate level.