Just a thought- how would everyone feel if the character in question were not a druid, but...
1) a fighter/paladin/ranger/barbarian who refused to take part in problem solving, diplomacy, or NPC interaction? Or a fighter type who chose sub-optimal weapons/feats because he enjoyed the uniqueness it gave his character?
2) a rogue who had sunk most of his skill points into skills other than pick lock, remove traps, move silently, and hide? Or who didn't want to play a killer-type rogue and didn't use his sneak attack?
3) a wizard/sorcerer who focused on divination or illusion, with few direct damage or buffing spells?
Are these characters failing to pull their weight? Does the rest of the party have the right to enforce certain choices or play styles on another PC because he isn't optomized?