Umm....probably because he's not a kitten any more. Kneading is especially seen in kittens who are abandoned or taken away from their mothers at a very young age (they should be with their moms until they're 12 weeks/3 months of age).....it also may be because he's not fixed? If he has been neutered, well, every cat is different, just like every person. Little kids LOVE hanging on mom/dad, giving kisses and hugs....once they get a bit older, very few still do. Cats are no different. Some will stay sweet and cuddly forever, some will hate cuddling, and kittens who've never wanted to cuddle may become little lovers when they get older.