Of course the thread’s a joke, and nobody begrudges the ways (within laws and ethics) that retirees spend their time.
Think of the dad raising a young family, or a young guy yet to get his career going. Then too much sports can crowd out either social obligations or the further enrichment of the mind or whatever.
Oh, I’m not arguing men with families don’t have obligations. Or grampas like me. I love my grandchildren, and I have a very firm sense of what I want to pass on to them. Neither stepson is into sports much, and I’m going to make sure my grandkids have a little knowledge of how to play certain sports...if they’re interested. Sports and a few other things their parents might not be capable or able to teach them (music, history, etc.)