According to Osho, he continues tirelessly because realization flowers as compassion: the body will perish anyway, so let it be spent calling out in love. Whether people change or not is secondary; his only responsibility is to let the message be heard and light a few lamps. Opposition is destiny’s counterforce that also awakens seekers. He counts the friends, not the enemies, and serves until this last life ends.
He speaks from love because life is short, and lighting even one candle is worth it, even if many don’t listen.