He criticised Bernie for one thing, and it was the energy goong into a presidential campaign which Chinsky felt would, win or lose, change little. That in the end you need a groundswell of local groups, each taking over control from the lobbiest, and pushing for change.
Voting for Hillary makes sense, since in his view, it doesn't matter too much who the president is, if you can't get the people involved and winning (people were involved in the occupy wallstreet protests, but they didn't win any great changes, after the 'victory' of occupying public spaces wore off, the people felt less effective) So it takes more than people and good will to change the wolrd, people also have to believe, and to generate belief you have to win.
Look at Iraq, the Iraqis don't believe in democracy, they didn't win it. It was never part of their culture to begin with, so the idea that it could be brought their by American bombs was fudamentally flawed.
Look at Occupy Wallstreet; the people felt they were winning there, for a while, and eventually their movement stalled (i wouldn't be surprise if the FBI got involved, if they were seen as a threat to national security) Chomsky champions this kind of people movement, from the civil rights movement in the 60s, to the anti-war movement in the 70s. Up to the Occupy Wallstreet movement in 2008-2011.
So it is no surprise that he said 'vote for Bernie if he wins the nomination, but Bernie should really be spending his energy on a grass roots movement - because that is the only thing which has ever changed the world.'