Don't disparage someone for enjoying something you don't. It's about choice and allowing people to have the life they want to have.
Cut the sanctimonious attack on intelligence. I have a doctorate. I love going to museums alone. I have no desire to ever have kids. Ever.
But nothing makes me smile like being able to witness the purity of joy and awe as someone learning something new. Child or adult doesn't matter, but children show it more cleanly and plainly IME. I like helping and I like educating. Does that make me moribound? Because I get a dopamine hit when I spread knowledge and understanding?
Plainly speaking, you and I are total and complete biological failures. Life's only objective purpose is procreation - going back to self-replicating RNA molecules. The genes that perform best are the genes best at replicating themselves.
So before you go spouting off some slop about how someone has a "moribund" mind, maybe remember that we're the ones that are defective. But that's okay, because we are all more than our contribution to genetic diversity.
Act with more humility and kindness. Be confident in your own decisions, and maybe you'll act a little less like a shithead better-than-you-know-it-all.