Complete overreaction. Valve is handling this situation properly. They pulled the game in a timely fashion and are offering refunds almost no-questions asked.
You want to be mad at someone? Be mad at Hammerpoint.
Valve gave them everything they needed to scam people down to control of the forums, they are just as liable. There shouldn't have been a need to offer refunds in the first place and now they are even letting on that this game could go on sale once again after the mythical features have been added. A lot of finished games don't even get approved by Steam and to have this happen and to give them another chance is just ridiculous.