Yes, all groups are different. But the general idea of therapy group is different from that of a support group. In a therapy groups it's ok to point out something to other group members they may not like in order to make them see their defenses and inconsistencies, just like it's accepted for a therapist to do that with a client, but in a group that could get confrontational and genuinely hurtful. Those situations are unpredictable and often uncontrollable and, therefore, are difficult to handle even for an experienced therapist. That's why I am not a fan of therapy groups, but I have found support groups generally helpful.