Of course it's an stupidity making a new Wikipedia for a same language. But at this moment, it's a fact that Valencian is not Catalonian, but there is a lot of people saying that Valencian is the same as Catalonian. We, the true valencian people (people who born in Valencia and has a huge legacy of valencian parents), don't accept this term, because we know our real history. We know facts such as when Joanot Martorell (a historic valencian writer) wrote Tirant Lo Blanch many centuries ago, he said that he wrotes the novel into "the beautiful and rich valencian language". Examples like that, we have a lot. Is about those facts because we want to make our own Wikipedia.
History is irrelevant. Two languages are the same if they express any given idea with the same sequence of words. It doesn't matter if they are used by completely different people with unique cultures, they are still the same language.