This is short-term pessimism, inline with the common dystopian future of sci-fi. It is really difficult to predict human behaviors and technology in the long term. Humans have the ability to steer things to their advantage so interesting things can happen. Just for kicks here's a more hopeful approach that I've heard...merge AI with the brain like Kurzweil was predicting. Imagine if everyone was a genius and telekine…
I think this is already happening. In fact most AI pessimists don't consider that "man + machine >> machine." Consider chess. Kasparov's defeat happened in mid-1990s. Machine is considered > man. Yet, in freestyle chess, where players are allowed to consult machines, we have achieved ever greater heights of performance. In chess today, any sufficiently advanced chess engine can be incorporated into a (man+chess-engin…
This worked between about 2008 and 2013; but those days are long one. Engines such as Stockfish 8 surpass both humans and human+engine "centaurs". That is, incorporating a human into the loop only makes things worse.