It's kind of a neat moment for tanks, but honestly I think things like tanking Susano's sword are more interesting than just 'okay I have to hit the lb button now or we die.' It's kind of neat here and there but I agree it's not well designed. Tank lbs are either virtually useless or they're 100% required with any middle ground being really rare if it exists at all. Really, healer LB 1 and 2 suffer the same fate, who ever hits healer lb 1 or 2? 3 only gets used because of the aoe raise.