> Surely the warranty and liability disclaimer found in licenses like MIT exists for a reason
Obviously IANAL, but I entirely don't see how the WTFPL (which does not ask the consumer to accept any restrictions) would create an implied contract (which would seem to be a necessary precondition for a warranty obligation)?
IANAL either, so my own legal theories are as creative as yours, but I'd like to offer the following data point: All unrestricted open-source licenses that were written by actual lawyers, from MIT to CC0, have found it necessary to include such a liability clause.