At least we can definitively answer that question now. No. The value of bitcoins is determined by the supply-demand ratio, which effectively means the amount of buying and selling on the exchanges. It has nothing to do with mining difficulty or rewards. Mining difficulty protects that bitcoin network from being compromised by bad actors (Cf. 51% attack). Mining rewards influence the mining difficulty, since they are an incentive to mine. But neither of these things affects the value of bitcoins.