It is not because of ethical reasons, it is because of resources & they do not feel like it.
Excenmille had his little gang of rugrats in FFXI. If you wanted, you could make any perverted emotes directed at them as you please. You could do it to the NPCs in this game. So, being a NPC or PC is irrelevant.
This is like the glamour topic; of how it would not be "FFXI like" to have jobs clothes and weapons to crossover, but the previous Final fantasy mmo allowed it "Face palm"
Excenmille was available as a trust. He took damage, grunted when hit, bleeds, & eats dirt like the rest of the players. People also ran by & made emotes at the kid. So I don't see the ethical issue here. If you don't have the resources, or just don't feel it is worth it, say so. Not these BS answers which contradict one another.
Would be cool to play as children, but it may not be worth the resources or time. I support it. This just seems like something out of their reach in terms of implementation imo.