Jesus had just cast out a demon from a man possessed (Luke 11:14). As usual, two classes of people reacted to this event. The first were the skeptics. They just did not want to believe that someone would speak to demons and they would simple obey.
They had seen many people possessed and had been helpless to offer any solution whatsoever to the plight of these people. They probably blamed the sufferers for their state and only God knows what exercise in futility they must have subjected those unfortunate people to, in the bid to exorcise the demons oppressing them.