I agree with Bon Clay on one thing: One Piece really is a show. But. It's not "just" a show. Saying that OP is just a show is like saying that Coppola's "Apocalypse Now" is "just" a movie and Clash's "London Calling" is "just" an album. OP is a work of art. It has it's meaning, message, style, story and characters. It is a document of it's time. Just like every other TV series, movie, book, picture, photograph, album, play, comic book, building or sculpture. It is also a document of one man's work, and an incredible work at that matter. In this case, of a man named Eiichiro Oda. Oda is an artist. He uses all his freedom, imagination and creativity to create something, by which people should remember and appreciate him. He works his butt out almost every week so that he can make people happy, to deliver them his thougths and to make a place in the history for himself. So, when you change a single scene, single cell or single detail in that man's work you practically mock him and everything he does. And that's exactly what 4Kid$ does. And there's probably nothing worse when your life's work gets bashed by some low-rent, money-making TV company for kids, in a low-rent nationalist, over-religious, terrorist-frightened, traditionalist, war-crazy country, whose president is so dumb that he can't put together a normal sentence, and whose large number of citizens is so stupid that they can't find Russia on the world map. And the funny thing is: their leaders keep saying that their country is the living symbol of freedom and democracy (and at the same time, censorship is very active in every pore of their society). The point of art is freedom. And that's what makes Oda a great artist: he isn't afraid to say and show what he thinks.
And that, my friend, is why you can't say that One Piece is "just" a show.