First of all, a more reasonable request would be to ask people to disable Adblock on the site, as opposed to uninstalling it. After all, there are websites out there that are a cesspool of pop-up ads, and disguised links that lead to more pop-up ads, and no one should put up with that.
Second of all, permit me to doubt that The Escapist is financed with ad money, given that I'm currently seeing no external ads on the site whatsoever.
And third of all, regarding why Extra Credits is leaving the site, there's more to it than just the lack of payment. Read the updated topic [http://www.escapistmagazine.com/forums/read/18.305970-Extra-Credits-leaves-the-Escapist-UPDATED-WITH-REPLY?page=1].