I think there's more to it than just humor because then we could take all mocks to DOA just as humor as well. Humor can be applied to everything but that doesn't seem to be the case when it is only applied to the same characters.
Yes, humor generally comes at the expense of something/someone. But things can be criticized, and funny enough, there are certain implicit elements that are connotatively linked to the jokes, but that's part of what makes the jokes funny. If you're catching onto the themes, it's kinda supporting the rhetorical angle that the selection process employed is rather transparent and unsatisfyingly superficial. Which again, is the "point" of the jokes as well as the source of their humor.
As for "humor can be applied to everything," sure it can, but I don't have to make fun of everything to make fun of anything. I'll leave the jokes that I don't think of or that I don't think of as funny to others. It's not like anyone's joke policing (except maybe you) saying "You can joke about those things but not these other things!" If you can't take jokes (with some rhetoric attached), you're not going to survive long in any community.
Not long ago people were asking why other communities don't play DOA. Will people come to DOA to earn money?, most likely not, they will earn more money with SNK games. Maybe to try their characters in another game? maybe they could make friends and that's a way to keep playing a franchise but if they just find out their character is strongly unwelcomed by almost the entire community that's unlikely.
The DOA community wants more players, sure. But that doesn't mean we'll eagerly accept anything so long as it nets more players. For example, what if KT did a crossover event with Fortnite where you could unlock exclusive costumes, stages and characters in DOA6 by playing Fortnite? That would almost assuredly bring in some new players. Would it be worth it? Maybe to a few, but I'm not obligated to support it by default for that reason alone.
As for cross-community bias, I think Nico is a miserable little shit that should be purged from existence (my sentiments towards Diego are not much kinder, for the record). But the Japanese like lolis and pseudo-lolis and what they like is gonna trump what I like any day (at least where KT is concerned). I'm perfectly within my rights to say that, and in my experience, my disgruntled opinions won't drive away the handful of people that can actually tolerate playing this game currently. So am I going to hold my tongue for another blue-haired loli that will probably look and play like shit
* just because she's a guest character? No.
*"How do you know that when she hasn't even been officially revealed yet and you haven't played her?"
Well, historically I don't believe any of DOA's guest characters have ever been positive additions due to awkward integration in a system they clearly weren't designed around (except Akira in a bizarre, offbeat way), and aside from that, none of DOA's wholly-new characters have been impressive since Rig, which I believe to be a result of poor gameplay design philosophy and lazy animation quality.
Sure, that's my subjective opinion, but I'm allowed to express it, and frankly my predictions are rarely wrong, whether they're addressing objective features or merely my subjective take on forthcoming content. Time and time again I predict how things will turn out and people tell me that I'm just being negative and cynical. Then the thing drops, and sometimes they whine about it more than I ever did. There's a long, documented history of it here on this very site.
Also, I thought DOA was about the fighting, why a loli can't bring excitement? she can bring a play style that's lacking in DOA in comparison with SC VI for example.
So, from my perspective, this would qualify as a joke. A loli can bring excitement, but there's simply no evidence to suggest that this one would. Especially in place of 90% of other options they could have gone with, all of which could be argued to bring excitement in the same or equal volume. The SCVI example is just pointless.