I don't even care that they might watch me. I care that they might use my computer's resources to do so; or might start making the extension do other stupid stu

I don't even care that they might watch me. I care that they might use my computer's resources to do so; or might start making the extension do other stupid stuff, like injecting ads for Avast AV. "Not caring about cookies" doesn't cost anything, CPU-wise.