"Bookworm" and "cinephile" sound like appropriated insults, whereas in contrast "hardcore gamer" sounds like one thinks more highly of themselves than of others. Maybe that's what gamers need: an insult to appropriate.
Oh really? I honestly never thought of either as pejorative. I like bookworm especially b/c there's an actual history behind insects (weren't actually worms) eating and boring through book pages. "Cinephiles" is interchangeable with "film buff" too, so that's another option.