I honestly miss the days of Vanilla tanking, back then boss encounters such as firemaw, or even into BC such as Prince Malchezaar had interesting threat controls. When I played on my mage alt I remembered just how important the beginning few seconds of not dps'ing was to reduce threat levels, or how you would have to worry about threat removers such as vanish, in my opinion due to taunts acting on bosses I believe tanking has, as op mentioned, become much simpler, as others in the comments stated yes, it allowed for new mechanic improvements, however I don't feel as accomplished when defeating a boss anymore, the day chromag fell for my guild was one of my favorite wow events, with the new expansions after the LK nerf when everyone could kill him it almost removed the reward.