It's human motivations which are not necessarily "well attached" to human motivations, to the extent that one human wants to benefit at the expense of another (which indeed works increasingly badly over time - people clubbing each other to death is one thing and humans throwing nuclear weapons at each other is another thing; but this has nothing to do with AI or superintelligence and what-not, and everything to do with basic human selfishness powered by increasingly better technology. In this sense there's no difference between corporations which are nominally supposed to operate within the law but in practice do everything to bend and change laws to their benefit, governments which are nominally supposed to operate in the interest of the people but in practice are run by people operating in their own interest, or machines programmed to profit at someone's expense, the root cause is always people fighting people in the hope to gain something, and people fight because they do. When a machine evolves with no human oversight and causes some damage that'll be a sort of AI apocalypse - this is IMO the existential threat number 1000000 on humanity's list.)