Part of the problem is that the recent increased value has brought in more miners which decreases the amount any one miner can expect to realise thereby making it, in aggregate, more expensive to mine. Mining and mining successfully are two different things - as anyone involved in the Klondike gold-rush could testify.
The process does not work like that. As more Bitcoins are mined (well in fact mathematically found) the level of difficulty is raised, so it takes more work to find the next bitcoin. The whole process was designed to make it harder to find valid results over time/coins found. In the last 6 months the level of difficulty has increased by nearly a 4x and over the last 2 years the increase has been 614x.
The original designer of the process was a very clever guy as the whole thing is built around a process that builds complexity and therefore scarcity as and when the concept goes main stream. The issue is then backed up by the fact that there is a finite number of Bitcoins that can be found. For the people involved in this 'world' this finite number is what is driving them as it indicates a limited resource - few people seem to have noticed that it is possible to have an infinite number of Bitcoin like solutions and at the last count their was already 1,300 different coins around.
Even a Bitcoin has zero scarcity as while there can only be a maximum 21m of them they can be subdivided. Currently the system supports division down to 8 decimal places, but even this can be increased. Again this drives the current concept of scarcity as if you own a Bitcoin it could 'become' far more valuable if such a change takes place. The reality is far more mundane, any state or business that wants to use a coin based system will just deploy their own and mine the coins themselves.
