Under the American rule (as opposed to the English rule) loser pays is very rare. Specifically for patents the law only authorizes them in "exceptional cases". In this case they were ordered for filing numerous frivolous lawsuits. Nothing in the scenario you outlined suggests anything exceptional. Defendants are allowed to defend themselves.
If a court finds a defendant meets this high burden as to the plaintiff's actions, then yes I think the real parties in interest behind the corporate veil should be on the hook. What's the alternative? That defendants who were the victims of frivolous lawsuits have to pay hundreds of thousands of dollars out of their own pockets? Who knows what assets had to be sold to raise that money or whose livelihood was destroyed? How is that an equitable outcome?
If a court finds a defendant meets this high burden as to the plaintiff's actions, then yes I think the real parties in interest behind the corporate veil should be on the hook. What's the alternative? That defendants who were the victims of frivolous lawsuits have to pay hundreds of thousands of dollars out of their own pockets? Who knows what assets had to be sold to raise that money or whose livelihood was destroyed? How is that an equitable outcome?