Nobody is saying it's "morally reprehensible"
Of course they are. "Vain", "shallow", "attention seeking", "immature", "showing off", "weird", "silly", "unprofessional", "what about my nine year old daughter", "would you want your child's teacher doing this" and all the rest of it. The whole tone is one of moral superiority. How can anyone fail to spot it? The thread is dripping with it.
But when you point out that they're making a ridiculous value judgement, they just deny it (case in point, but you're not the first and you won't be the last). Why? Well, because it's so patently not a moral issue! Because it's absolutely ridiculous to turn it into one! Because it's a sign of someone who just doesn't like women making themselves visible and being proud to look nice, but doesn't want to ask themselves why they feel this way about it.
And on some level, you lot do realise this, which is why you moralise it in one breath and then immediately deny that you're doing it in the next.