Hi Nikki;
These people don't want a debate. You'll notice that the person (or persons, I'm not sure which post you are referring to) did not stick around to discuss their ideas or defend their conclusions. They simply posted, then ran away like frightened rodents.
This website has been accused multiple times of being funded by NASA, the NSA, the Illuminati, George Bush (?), Barack Obama (?!) and the reptilian aliens (!!!).
Just to be clear, we're not paid to do this by anybody. The domain fees and hosting fees are minimal and are paid for by me, out of my own pocket. By the time 2013 rolls around I will have spent about $250 or $300 in fees to run this website.
Why would I do that?
My motivation is simple: Every time I think about stepping back from this debate, about letting someone else do it, I think about the kid (there's been more than one now, but this was my first experience with it) who came up to me after an astronomy presentation in 2007 with tears welling up in his eyes, because he was terrified that the world would end in 2012. He'd heard it from a classmate, who had heard it from an older sibling, who had seen it on YouTube.
I think that initially I was a lot like some people who happen across this debate and don't believe that it is serious. "How could anybody actually believe this?" was my first reaction. So, please believe me, I understand your anxiety. I also understand your frustration and anger with those who spread this hoax.
I don't know about all of the other posters or site members, but I feel that their motivations are probably similar.
I will not step back from confronting this hoax. Please feel free to come back and ask questions as many times as it takes for you to feel better. We will answer you as best we can, and as often as you ask.