Seeing as WT is a pretty new investment, and not a bad one at that, I don't think it's going anywhere any time soon. As it's been said already, the only reason ridership is lower on WT is because of the capacity. Invertigo at KI is just as popular as FoF in my opinion, but it gets 1,150 less riders per hour (from KI website).
As for the "chaos-style rides," there was one at Michigan's Adventure that collapsed, resulting in many injuries.
http://www.rideaccidents.com/2001.html#jul30b