If you aren't lucky enough to have them be of the base class you have to create an empty template superclass just to satisfy the compiler. Objective-c has a better solution and things can dovetail without being in the same class.
"Doing it wrong" implies that Swift is just inherently better without making a real argument about why that would be the case. And the OP is actually making a pretty convincing argument that it isn't.
Swift is awesome at doing things better than obj-c and it really does reduce a lot of template code. But maybe not in this particular instance (right now).