Good vs. Bad

In class we touched on the subject of mastery, skill level, and good vs. bad art.

Some argued that if one masters a certain aspect of art, then they are "good" at it, whereas a child or someone with less skills creates "bad" art.

I don't think that art can ever be good or bad. Art is simply art. That is why I do not understand the reason many people go to school for art. It is one thing to gain more skill and to learn different techniques, but I don't think that learning these things makes you any better of an artist; it just means you know things you didn't use to. It's like taking classes on drawing where you are taught how to draw, but in their style not yours.

Does knowing different techniques make you a "better" artist, or just more skillful?