The scene of the parable is being repeated: it is the same as with those people who were invited to the wedding feast. Some are afraid, others have their own concerns, many... make up stories or give silly excuses.
They put up resistance. That is why they feel the way they do: fed up, all in a muddle, listless, bored, bitter. And yet how easy it is to accept the divine invitation at every moment, and live a happy life, full of joy!