My OH hates Christmas. Says 'why should I like it? I'm not a child...' whereupon I point out that I and my kids (none of whom are children, now) all love Christmas, that he gets big meals, lots of booze, to sit in front of the TV and not move with everything done for him, plus presents, so what's not to like?
He did concede that his POV was a bit daft after that. But he does grump about everything generally.