If people enjoy it, then they should do it. It's not hurting anyone, and it is simply another form of dressing up. For me personally, I'm not into it. But that's my personal taste. I find nothing wrong with it, it simply doesn't appeal to me aesthetically.
The thing that I dislike about it is that the face is frozen while the rest of the body is moving. I find that disconcerting, like a bad dream about mannequins or dolls that come to life. In anime, the eyes are huge and expressive. But the eyes on a mask are dead and lifeless. It may look all right in a photo, but in person it's a little disturbing. I find it as creepy to look at as overused botox.
I much prefer to see a living face.
My costumes in obsessive detail at my website
And no, I'm never going to update my website. EVER. Quit asking me.