User blog comment:Deshiba/Taunt rework/@comment-24420226-20150601193849

The point of taunt is to force carries to attack non-ideal targets (the tanks) and prevent them from kiting. It overlaps mechanically with stun, but so do fear and knock-ups (and snares slightly less so). The major difference is that a taunted carry is still doing damage which is somewhat counter-intuitive, as the goal is to stop the carry from doing damage at all (even if it is against a beefy tank). Hence, a 2/3 taunts cut the taunter some slack by reducing the damage they take. Rammus already has a good tank steriod as well as a huge incentive to get lots of armor to survive auto-attacks, so his taunt instead has that extra utility to help his team.

As for Galio in general, the only thing keeping him down is his low mobility making it difficult getting into position for a good ult. That and his lackluster early game in either lane or jungle.