I wanted to reflect on the bitcoin difficulty, that maybe is silly, because this fashion the theme of attack of 51% or selfish miners

     What if a change in difficulty as you are and the remaining 2000 blocks to undermine with a difficulty of 700 million the price of bitcoin is desplomase such levels that most of the hasrate abandon the network that was not profitably mined, imagine that he would tarry hastrate to 10% of the current, the difficulty really 700 million would thus undermine cost 10 times a block which would give an average of 100 minutes per block, little discouraging that hasrate quedase network and creating more currency in which no serious vicious cycle of declining hash mined.
What do you think of this? Maybe I miss something and this is impossible.