It's all about the money honey.
WGT has raised more than $20 million dollars in venture capital. I am sure they need to pay these investors back at some point by some means.
I don't imagine the credits we buy add up to a hill of beans when stacked against their debt load and it's my guess that. WGT's income comes from having our personal information and by selling ads. You need page views to validate the dollars advertisers are willing to shell out for these ads. When linked thru Facebook, the ads and their revenue belong to Facebook and most of the WGT ads are not visible to the user via the Facebook portal.
It also appears that WGT has hooked up with Google as their preferred search engine and yet another source of income, and we all know how well Google and Facebook get along.
WGT's plan for using Facebook is only to drive users to the WGT site. This is a quote from an article in VentureBeat 3/16/10: "CEO Yuchiang Cheng tells VentureBeat that the company will use some of the new cash to launch a basic version of its game on Facebook — although he emphasizes it’s designed to be a marketing channel for the game website."
I am sorry for everyone's pain having created their accounts via Facebook, but after reading all the posts from WGT (or lack of with any clarity) I believe there are no plans to fix this Facebook issue (it's really a pretty simple fix), it's our issue, not WGT's.