I think the point Rama is trying to make is that it isn't a scientific theory, because it isn't even in the realm of science. Nobody seriously studies whether the earth is round or not, because it is blatantly obvious that it is round. It's a fact in the same sense that "doors exist" is a fact. There isn't a "door theory" dedicated to answering the question of whether or not doors exist, is there? Of course not.
However, for the purpose of this website, I am willing to humor the flat earth "theorists" and refer to it as a theory.
If there is a website dedicated to the "doors don't exist" theory, I'd humor them as well. Heh, I can see it now:
For: "Maybe what you think are doors are actually just really thin walls"
Against: "But we can walk through doors... we can't walk through walls"
For: "Maybe you are phasing through the thin walls, and the government is suppressing the knowledge of phasing technology"
Against: "But we can actually see the door physically open"
Tom Bishop For: "Nah, that's just perspective"