Plus if they mined all the coins themselves it would lower confidence in the currency (especially if it meant they aproached 51% of the mining capacity) which w

Plus if they mined all the coins themselves it would lower confidence in the currency (especially if it meant they aproached 51% of the mining capacity) which would entail that the price of bitcoin would go down. Possibly before they got their moneys worth. It is a lot safer to make money selling them to lots of people.