A defender Titan never has to worry about the chalice, just pop the bubble and the "Blessing of Light" heals you and any other team mates that wish to use it. Titans are not useless when you learn to use them properly, I have had to save warlocks who self-rez in nightfall only to be dead again prior to their super coming back. You see nightfall, strikes and Raids are about team work, and when the team works together, the missions are easier and faster to complete. When you get that one person who has no concept of teamwork, then well you know it all falls apart. All classes have their benefits, it is just great to play with people who have figured out how to use their class to the fullest. So I disagree with you as no class is useless, it is the controller actuator that is the issue.