ir·re·spec·tive
ˌi(r)rəˈspektiv/
adjective
adjective: irrespective
not taking (something) into account; regardless of.
As in, it doesn't matter what people actually are, most of them play female characters. This has nothing to do with "respecting" people.
Personally? NO reason. Society wise we seem to have a problem with it. Ask the people who decided my elementary/middle/high school wouldn't have boys days anymore why. I have theories but I'm not the one making decisions. If I had sons I'd be flying the carp flags and gifting them little samurai dolls and giving them treats... just like if I had daughters they'd get little kimono dolls and goodies on Girls day. It's cute and makes for a fun day for little ones.