Alright, time to dust off this explanation again.
Shipping is about relationships and exploration. Ship is literally short for relationship and was originally a term for all relationships. OTP was the one you liked most but there were all things like BroTP (you're favourite friendship) and family was referred to as siblingship. It is only really recently this term has been narrowed down to just romance/sex.
Also to say "only if they're moral and whole and fuffly uwu" is the same as saying to any writer "you can't explore dark themes it's not nice". If I want to write about how characters might be in an abusive relationship, why should I not anymore than a writer of original work should not? Look at things like Harley and Joker. Are you saying people shouldn't be able to explore that? That it can't be interesting? Are you saying all content fans explore must be exactly what you laid in front of them and must adhere to your work strictly with no room for their own views?
And if I look at two characters and go "I think those two would have good chemistry, they like similar things and have similar values despite the author never putting them on the same page and seeming to have no intention of doing so" why should that be a problem?
Also people need to get off their high horses about fan interruptions and content (even Romeo and Juilet is a retelling of someone else's poem) and so much of what's now considered classic would also be considered fanwork by today's standards. Yes, some people get carried away, but if they didn't love your characters and weren't invested, they wouldn't be interested in shipping. Honestly, I think most people who complain about shipping have no fandom experience beyond the 12yos in their comments and don't understand what shipping is at all.
I'll also direct you to this video that while specifically looks at gay fanfiction, still answers the question of shipping in general pretty well.