You can't take the piracy rates or sales for two completely different games and then assume that copy-protection is the sole distinction between them.
So your point is that apples and oranges can't be compared so no one should make any reasonable comparisons too? You can't compare Deus Ex and Call of Duty but that doesn't mean you couldn't compare Call of Duty and *pick a popular FPS that has a similar level of DRM here*. All comparisons are not invalid just because a single one is. Make more reasonable comparisons should be your point, not a blanket statement that comparisons cannot work period.