There is a differences between "cosplaying a character to match everything, from the costume all the way to make-up and expression" and "I just want to show my naked self while wearing the wig and some attributes that makes me look like i'm cosplaying a character". One's an effort, the other is just being a whore.
And Pan Piano has been doing that thing recently and it's rather annoying (to me, at least). She's actually willing to dress up as a character based on what stuff she played on her piano, but now after learning that nudes sells best, she just using nude-'cosplay' teaser to rack views. That's just not cool (to me, at least).
yes, maybe in your own opinion, just wearing a wig and some other bits except clothing is a cosplay, but to me it isn't. The whole thing is the costume that is worn and how close you are replicating it to look just like the character. If we go by your definition then I can just be like, have a cosplayer just wear some random ass casual clothing and wore IRyS wig and say "This cosplayer is cosplaying IRyS. How wonderful."
It's just not it, man.