It's even scarier to think about paladin learning curb that exhist if you started playing this expansion (not including s12). Things like positioning, cd management, etc.
Playing every healer besides priest this expansion I think it's pretty safe to say that it's 10x easier to plug and play different teams on my shaman, druid, and monk (not to mention more fun). Each class requires a different mindset, however, none are as hard as healing a 3s comp as a paladin without tremor totem or mass dispel on your team.
+rep to this post. Explains pretty much all. For each person the difficulty of handling a class changes (eg: I can't DPS :'( lol) but as a holy paladin, I don't think we are the easiest healer class to play anymore. Back in the days people were not that into CC and there weren't that many CCs in the game so we could keep out partners topped easily. The problem now is not the healing output but the minimal time that we have to unleash those heals and still being vulnerable to godknows which potential CC. The only thing I personally want and think that not many people would disagree is that to buff the Hand of Sacrifice spell so that it becomes undispelable...
Even if you are a rank 1 positioner, the instant CCs followed by casted ones will catch you after some point