nostalgia-obsessed person; fuddy-duddy
Derogatory internet slang for someone who constantly praises the past and dismisses the present, often used in online communities.
That forum is full of nostalgia-obsessed people who only praise old anime.
He's a typical fuddy-duddy who immediately criticizes new games.
Combination of 懐古 (nostalgia) and the derogatory suffix 厨 (from 厨房, internet slang for an annoying person).