People aren't investing in bitcoin because it's currency of the future.In some parts of the world, bitcoin is still a more efficient and cheaper way to transfer money across borders, and several remittance startups make use of this feature. Bitcoin's cost and speed advantages, though, are being eroded as traditional channels improve (and the network's fees continue to increase), and liquidity remains a problem in many countries.
I think the two- and three-digit price is very common as a result of speculation / manipulation, and let's face it, everyone here has the opportunity to enrich themselves this blessing, and who does not want that part of it.
Bitcoin used as a 'currency' has steadily grown in various sectors, the Silk Road may be one of the most important. However, this relatively cheap price will support transaction activity, I imagine it is still very much in single digit territory.