You seriously think he was just sitting on Ahch-to milking his Thala Siren? He was there for what, thirty years or so? A Jedi has needs, man.
Seriously, for all we know he was thinking about settling down with one of the frog-ladies and starting a B&B. Maybe hatching a few spawn of his own. Then everyone’s favorite manic pixie dream girl Rey comes out of nowhere and fucks everything up. Luke’s one shot at happiness squandered because some chick barges in with his rusty, old laser sword. What the hell, Rey?
This film could have been so much more, but I’m not blaming Rian Johnson here This is a clear directive from the execs at Disney who have a very strict “no inter-species dating” policy, but they’re totally okay with the idea of anthropomorphic dogs and mice owning other dogs, though (This is truly weird, Disney). I’m guessing Goofy is a widower, but the guy raised a kid all on his own. At least let him date.
I really do like The Last Jedi film. It’s a very well done addition to the Star Wars films. Sadly, whenever I watch it I think of the lonely frog women of Ahch-to waiting in vain for their farm boy from Tatooine to return.