I'm not sure the bubble is bursting exactly, but at least in the RPG/boardgame arena, people are becoming more skeptical.
For one, there have been a number of KS projects that were funded many times over, yet the creator never finished the project. And almost all of them are several months to a year late, with only a handful being on time or early.
It doesn't help that many KS people will start a new project before their old one is done.
That Mike Nystul guy did that, and apparently he has spent all the money, so his projects probably won't be coming out.
http://www.tenkarstavern.com/2013/03/the-king-of-wayward-kickstarters-axes.html
For another, while the original intention was to facilitate projects being made in the first place, we've seen companies start to use it more as a pre-ordering system. Which is fine until people start realizing that they are basically paying nearly twice as much for a product as they would if they simply waited for it to go on sale. Like $100 for a big hardcover book as opposed to $60.
I think that's what is hurting the Freeport KS. I don't think there is any doubt GR can produce a quality product on time, but $100 is a lot to swallow, especially when they even admit on the KS they will be selling the books to retail for $55 each (and so discount retailers will probably sell for $65 or so)