Another thing to remember is that our collective understanding of the problems evolve over time and often subsequent standards reflect this. XML vs JSON is definitely a case of this, as is the progression of CORBA -> SOAP -> JSON based REST services.
But sometimes things are complicated/messy because we're trying to solve complex problems.
That's not to say that there isn't a simple solution to a particular problem nor that we should strive to find it.
But to assume that there are always simple solutions to complex problems is itself a form of ignorance.