Not true miners obviously have incentive to destroy the bitcoin network.  This doesn't mean they are doing it intentionally.  What I have learned at this point is that if wall street wants to destroy bitcoin one of the ways is creating a slick, easy to use pool with great payouts and lots of incentives.   Miners will jump to them for easy "profit" and once the network gets 50%+ it's game over.  You think wall street would have a problem dumping billions of dollars they would never see again into destroying bitcoin?  They would do it without thinking and the billions lost creating a slick miner friendly ticking time bomb would be like you losing a dime in the couch cushions.