I agree that Druid is strong and slightly better when it comes to support, but it's not like there are worlds between them. Tempest, too, provides Fury, 25 Might and regen for the group. While Druid provides protection, Tempest provides vigor. Tempest can also share the aura effects with the group. While the fire, frost and shock aura might not seem as strong as a group wide magnetic aura at first, they still add up. It's additional CC, Burning and damage reduction, after all. And there are a lot of players out there who don't care about endgame meta compositions as long as they get the content done, even in T4 fractals. I did quite a few T4 runs in full celestial gear and groups without a Druid, and never had trouble or have been kicked or something like that. Quite the opposite, a few people even said stuff like "always good to have an auramancer". Sure, those runs weren't as fast as runs with meta compositions, but they weren't significantly slower, either.