Well, my logic there is that he came back from the dead just as TNG was one of the best things on TV, and ended up watching it during those late nights when everyone else was asleep, or he was stuck doing overnight guard duty at Oracle, and just... clung to it. Like a baby monkey. Because it's all about family and damnit he misses the rest of the Invaders. But Namor and Steve are busy off doing other things, and so he just sits there and... not mopes, really, but is sad and full of *sigh.*

I'm sure there's at least one story to be told about Jim attending a Trek con and completely unnerving whatever poor cast member gets him in their autograph line.