The spiritual master doesn't want to see his disciples suffer. He doesn't like to see anyone suffer. That's why he preaches Krishna Consciousness. He preaches because he hopes that if his disciples hear his instructions, they can avoid suffering. Sometimes the disciples are persistent in their wrongdoing and the spiritual master cannot help them. He must let them go their own way until they have suffered enough to want to again take up his instructions.
Lectures from a disciple, Vol 1, Pg 67, 3rd paragraph