dont forget that in 2016 btc income from mining will be half
but the value will be also very high, the current value already is about 100% more than what it was, so easily at this point will not count anything, incomparison when we were at 230
The price of bitcoin is not certain to rise. That is just a speculation. But the blockreward is going to halve, that is certain.
the point is that because of the certainty that the block reward will be halved, you have also somehow, the certainty the that price will increase
otherwise it's like saying that bitcoin is doomed to fail at some point