The problem with the design of retribution is that it relies heavily on seal damage, as much as 50% or more of the damage done by a retribution paladin is done via seals. Whats more this damage is delt passively & relies on RNG for it to work well. This means that the player has no real control over the damage he/she is dealing.
As long as blizzard stays with this design and does not change to to one that has a larger variety of active attacks with varying effects and cool downs (or on proc attacks) the retribution paladin spec will not get respect from the community & will be seen as the faceroll class of choice.