There's also apparently been some people reporting that they called the hotel asking about the $17k bill and not finding anyone who knows what they're talking about, but I can't find any of those posts myself.

I have seen a couple of posts mentioning that the hotel had never hosted a fan convention before and using that as an excuse as to why there was such a mix-up with the money -- this seems to be the text going around the most that mentions it, specifically this part:

Half an hour later, con security started telling everyone to go to the ballroom, coming in to panel rooms and getting everyone together.
When we got there, the situation was fully explained. The hotel had never seen a fan convention before, and they were freaking out over the costumed guests and the general hubub. They were demanding money they would have received later on during the weekend, namely the money the second and largest day of the con would have brought anyway.

So some people are extrapolating from that that the hotel just didn't ~*understand*~ how conventions were run and they were just ~*inexperienced*~ the poor tender fresh-faced babes, it's all their fault, but don't hate they too much, it's just their first time.

Except that, especially with it being a Marriott branch and all, even if it were a brand new hotel, they should have protocols in place from corporate on how to handle conventions since it's something that hotel chains deal with all the time. And "upper management" -- that the DashCon people claim are the ones this was coming from, not the poor housekeeping workers that have to deal with cleaning bodypaint off of the beds and bathrooms -- would have been hired from a pool of people with experience in the hotel business, if not just straight transferred in from another Marriott.

So "inexperience" is really a moot point here, at least as far as the hotel's concerned.