No, it wasn't and still isn't. The simple reason why people disagree with the theory is because that it doesn't make sense, or that it's just not logical. If a theory cannot be proven to be false, then it cannot be proven to be true. But that logic contradicts the fact that this game has a lot of hints leading to R=U.
Why do people think that the U-Guide's statement (about life-span) automatically rejects the whole theory, not to mention thier interviews, e-mails or newspapers columns include no mention of rejecting or confirming the R=U theory.
Also, just because the number of R=/=U supporters outweighs the number of R=U supporters doesn't mean that the theory automatically becomes dismissed!