Painting is a language no less than any written language. To think that one can through inspiration and talent can create something of worth is to think that one can write a novel without knowing the language or how to spell. I think the reason is that so many mediocre paintings exist they have become the norm. People hardly know good art from bad.
In order to create a painting with meaning you must the fundementals that make up the basic language and those things are drawing, perspective, color, composition, etc. and that takes a long and dedicated effort.
No one thinks a person could possibly play wonderful music on the violin without first knowing the scales. Painting is one of those hard earned skills that many think can just be done with talent alone. It cannot.