I mean it's still nice to share other peoples art right? I mean you did say not to do so but hey expanding the horizons isn't so bad toot toot~
There's nothing wrong with sharing art.
It's just that this thread (and I'd assume the entire creativity section) is for amateur/learning artists, and you can't really learn much from people who are just posting other people's art. (Like if I saw an exceptional piece, I might want to ask about the artist's process or techniques) Also professional art pieces are usually of high-quality and made by ridiculously talented people, so it would create an unrealistic standard for aspiring artists who are posting their OC.
And I did specify original content.