As above, those classes all had issues. Death Knights didn't even have a designated tanking spec back in the day - that's not really comparable. Enhancement is like a clunkier version of Ret Paladin, but it's a complicated spec with a lot of buttons - it's like that for a reason - it's supposed to be quite complicated. If you don't like that then I know rogue, for example, is a nice simple spec to play and is comparable to an elemental shaman in difficulty. Windwalker also flows very well and also has fewer core rotational buttons. Moral of the story: Different specs have different difficulties, that's how it's supposed to be, we don't
want every spec feeling the same and having the same level of difficulty.