Strict legality and validity are irrelevant -- proving the legality and validity would be an expensive and time-consuming process for the targets of these claim

Strict legality and validity are irrelevant -- proving the legality and validity would be an expensive and time-consuming process for the targets of these claims and most lawyers would agree that settlement is always preferable. 9/10 someone may win the suit against a patent troll but the cost of proof ($$$$) is extremely bitter to taste.