Definitely this. Conventions are in it to make money (of course). Creation sells it as a big-time experience with really big stars. They can afford to be choosy (although Terry has noted they have been bad at working with dealers). ReedPop is a bit more of a cipher but they can probably also go with this sort of a business model. I went to their Mission: New York con last year and it was mainly biggish names and most of the dealers were good and interesting although there was also a gal selling crystals and a booth for the NY Daily News although I wonder if there was some sort of a deal there in exchange for press coverage and/or having a purely local presence.I'm not sure about the US, but I imagine the model wouldn't be much different from what we have in the UK. Here there's really two types of cons: The ones that need the money, and the ones that don't.
If it were here, I can't imagine him being of worth to the largest organiser (they don't touch anyone unless they get a deal or they can see worth) but he'd fit right in with the second-largest as it's run by someone who's just interested in the bank. The only thing I can see being an issue from the tier 2 guys is that they run licensed conventions with CBS reps in attendance at the Trek one.
Smaller cons take whoever will buy a space. So I'm sure, even in his worse case scenario, Peters will still book tables, volunteer for panels and keep speaking to empty rooms and asking people for money that somehow won't be accounted for.
Get smaller and yes, they need the bucks, so they aren't going to care quite so much about reputation or whether the subject is on point, so long as the check clears for the booth or table. This is how friends of mine can sell their books at some conventions (not Star Trek-based; these are more like cons based in the Northwest which are more generalized). Plus it may not be in their best interests to look over every booth application or ticket sale with a fine-toothed comb, or they may not have enough paid or volunteer staff to do so effectively.