no . it's quite viable , regardless if you go for elemental + hunting banshee or RoF+Freezing Gale , plague avatar or any other combo . it deals good damage , has good defense and regen + meatshield (acid fiends are mandatory). . how can caster druids be bad ? how can any druid be bad ?
the only builds /classes that are suffering in Sigma are the assassins , but even so , a few of them are still decent and viable .