One of the issues is how you define "defensive" purposes. If you are locked in an ecosystem battle with opponents who are fighting on multiple fronts over years (Microsoft shaking down Android vendors, Apple suing to ban and restrict competition), then you yourself may never be sued directly, but your interests are nevertheless, still being attacked indirectly. It's like a Cold War where your client states are fighting it out against other superpowers.

Thus, is it "offensive" if Apple sues one of your customers over a stupid patent on phone number extraction via regular expressions, or Microsoft sues over FAT32, and you retaliate by suing them because they built a bill-splitting app into their product? Or must they launch a nuclear missile directly at your capital before you're considered justified in a counter-offensive?

The hope I think of asserting these kinds of patents is that mutually assured destruction results in detente. You build up a nuclear arsenal so that it becomes unthinkable by your opponent to attack, and this is undermined if you hold yourself to some kind of pledge never to use them, or never to use them unless your capital is bombed directly.

What the EFF is asking for is a nuclear non-proliferation treaty and test ban, but they are asking the weaker player (who has fewer weapons) to give up their weapons and give up making, and not the superpowers.