Agreed, I've found that shortly after taunting the 3rd boss in boondocks and the 1st and 3rd boss in The Vault as well, I taunt and sometimes the boss carries on going for the previous target, so my taunt has no affect.
Also, with regards to the Inciting Cry skill/talent, as it doesn;t apply 'taunt' atm it doesn;t activate spiked armor either.