That's true, but only if the thing they want is money. For example, a commercial software developer might fund lawsuits against its open-source competitor even

That's true, but only if the thing they want is money. For example, a commercial software developer might fund lawsuits against its open-source competitor even with no hope of recovering significant cash, because the goal is simply to destroy that competitor. Probably they'd lose eventually. The effect on the defendant would be big regardless though, and that's the point. A lawsuit doesn't have to win to be a useful economic weapon, just to survive long enough to inflict the intended pain on your opponent.