As far as I can recall--and granted, my working knowledge of the list is limited--the number of banned artists from the past ten years is rather paltry.
Part of that comes from the fact that, in early years, there weren't 1100 visual artists showing up with art to hang. Another is that, when the scale was smaller, the ability to monitor and police situations was an easier task.
With the scale of Artomatic being what it is, it's become necessary to set crystal clear guidelines, complete with penalties. That said, I think it's poor form to call people out. There's simply no need to make a list of people that aren't invited, especially when the goal is to bring new people into the group.
On the topic of charging people fees, I think you're all suggesting too low a penalty. If the goal is to dissuade people from blowing off their shifts, then the financial dig needs to be significant--at the very least, it would need to cover what it would take to hire someone to pull the shift these people are ditching. I propose that a participant is welcome to buy out of their shift, but it will cost them $300. That's obviously a huge deterrent from squelching on your shift requirements. That said, if someone is hellbent on hanging their stuff without showing for their volunteer hours, then it'll cost them a thousand bucks after registration and buying off their three shifts.
Yes, that's a lot of money. But if we're reduced to hiring shift workers because people can't be bothered to live up their commitments, then it we ought to bleed the slackers dry.