Teenagers date. it happens, and it's perfectly fine, even if one is slightly older and turns 18 before the other one. Plus dating does not necessarily mean they are having sex, so... I just don't see what the problem is with shipping a 16 year old fictional character with an 18 year old fictional character. I mean, IRL I am one year older than my SO, we started dating right before our shared senior year (16/17), so does that make me a pedo for one year of our almost 12 we have been together? No.
All of this, exactly…
People like hiding behind big words and acting “morally superior” (as opposed to what?), it makes them feels good and like they have a higher purpose. But sometimes you need to step back and look at things critically you know?