I think you'll find it is called stealing to copy something without permission, and copyright infringement can deprive the originator, like if someone copied the lyrics of a song someone else released 2 days back without credit. Modern copyright law is widely abused but that doesn't change the fact that taking art without permission is stealing, no matter what your personal definition is.
The stealing in the studio ghibli case is ingesting all of the studio ghibli art without paying them for it, and while outputting, clearly labeling it as studio ghibli style.
For now the community is its own thing, which is interesting in its own right. Maybe once we get more than 2 regular posters it might go unpublic