Art (and entertainment) is all about
interpretation, and that's what people who don't take heavy Humanities courses usually don't know. A painting may not be able to be changed, but artist's intent is still an issue because a painter may
try to evoke Emotional Reaction A out of me when I view it, while my experiences and thought processes may cause me to evoke Emotional Response B.
Sakurai (or any other designer of any other game) has provided us with his piece, a piece we cannot change (without Ocarina
), and we interpret that piece in many different ways. Some interpret it as he intended it to be (meaning the response he planned for was evoked), as a party game. Some people see different things, look for different things, and interpret it as a serious fighter. User interpretation of the source material is inherent to all forms of art/entertainment, including paintings, music, movies, books, and yes, even games.