I've considered not esting octopuses for that reason. I mean, I wouldn't eat a dolphin because of basically that reason, but at the same time I do eat pork (I don't actually care much for pork, even still.)
At the same time, I don't know. Octopuses seem completely incapable of empathy to me, so I bet they wouldn't even really mind if they were a civilization. I don't know.