I kind of thought it was a given that it was personal opinion that was crucial in deciding whether or not to believe in it.

It is labelled a THEORY after all.

And again, I want to stress how poor a source the so called interview with Square is, and also mention that the version of the theory presented in that website is ridiculous.

That's why there still is a point to discussing it. You see, I can google search "Rinoa Ultimecia theory" and find dozens of website on the issue, but 9 out of 10 present hopeless and lousy cases.

Another point is that there are still many who consider the theory impossible. largely because of the many ridiculous arguments floating around on the internet.