So, it´s a question of an assumed hashrate on which an assumed difficulty is based. Then big mining operators play that like a fiddle to fleece their investors. Small wonder that nobody in their right mind takes this mess seriously. Nonsensical production of a produce that has no volume on two-bit exchanges and constantly falls in price. It totally stands to reason. But the more confidence in this nonsense tanks along with the price the more it is supposed to be worth in future. Good luck with that.
Galdur, please read
https://en.bitcoin.it/wiki/Difficulty. In short when network hashrate goes up, the difficulty goes up as well to compensate it.
Relevant citation from
https://en.bitcoin.it/wiki/BlockThe difficulty of the mathematical problem is automatically adjusted by the network, such that it targets a goal of solving an average of 6 blocks per hour. Every 2016 blocks (about two weeks), all Bitcoin clients compare the actual number created with this goal and modify the target by the percentage that it varied. This increases (or decreases) the difficulty of generating blocks.
The fiat value of BTC has no direct relation to difficulty nor hashrate.