Imagine being a young or new collector. Imagine buying a seiko 5 after saving up for it and being so excited to see the mechanical parts with the see through case back. You watch the balance wheel and rotor turn and it just looks so cool to you.
Then some asshole comes by and tells you, "that's a shit movement, what a shame to display it"
I really am disappointed in people more and more every day. Just because a Lange movement is gorgeous and a joy to look at for people with the means to see it, doesn't mean that someone else can't enjoy looking at their entry level watch movement. Gatekeeping at its worst.
The reason to like or dislike a see through caseback can be design related, functionality loss, etc. To say that a watch with a simple movement which is targeted towards a person who is buying a watch at a lower price point shouldn't have its movement displayed because it's not a "luxury item" is asinine.