I'm not going to judge King on other reservations, I'll leave that to the rest of /co/ as no doubt others will get more said than I could in a post anyway, but what I will take up is this matter no one else will care about.
Now, giving the benefit of the doubt, he's likely writing from the intentionally ironic framework of these costumed characters making such observations, an attempt at reflective comedy from a lack of self-awareness in an already comical situation, but all the same the very idea to me that people who routinely dress up in costume for the sheer sake of it would even register such a thought, while in costume no less, and have any leg to stand on voicing the thought, is just batty, pun intended.
Could That man look less Bat man in his Batsuit of Batarmor? Yes, bat does he need to? I can't imagine why in the DCU of all places. A regular full plate would be fine in both worlds, ours and his, since it carries its inherent image of knighthood and all that comes with that, but since his world has already accepted the Batman image, among other things, upon adding the two there's just nothing less or more ridiculous in the elements alone or together. So, outside of a 4th wall view, where's the joke, Selina?
Had she made some sort of knowingly hammy Knight pun ribbing I wouldn't bat an eye, no pun intended, but the mind reels from where she's coming from to ridicule the habits of her already infamous cosplaying husband. This guy Bat-themes everything anyway, he had the JL custom make him a enhanced armor in his image, where and when does the gimmick start and stop looking ridiculous?