I actually want to expand this and say it's basically identical to how animals were used to make countries and their actions less intimidating/bad. Depict a country as a rabbit, an eagle, a bear, etc. They're disarming instead of scary soldiers.

This is the same. It operates on the same level and the anime girls take it further. It's also slightly enlightening when viewed this way because anime girls are also not really treated as human beings, they're treated more like creatures. Creatures doing bad things to other creatures is another form of distancing from the reality of humans torturing humans.