Very insightful post, thank you for sharing it. I believe the value of bitcoin is in the eyes of the investors. Those who hold it, and the marketplace of individuals willing to buy or sell is really what sets the price. If Bitcoin became usable, there's no reason the price can't rise to 100,000$ per coin, at the least.
There's a difference between "spot price" (whatever the buyers are ready to pay), short term value and long term value. In this article I was looking at "inner sources" of long term value. I also think bitcoin IS usable for certain things (trading, international value transfer) but a lot less for other things (buying goods and services)