@user_460797: There is a flag reason that filters out posts...

user_460797
2016-12-19T14:46:11-05:00

There is a flag reason that filters out posts that are randomly posted from a doujin without context.
Such a flag reason came through yesterday, since I can't find this post anymore, although the flag also mentioned tht it is poor quality.
But regarding Doujinshi uploads: I guess we have so many uploads and images that it doesn't really matters if there is one doujin post more or less.
Anyway, if it isn't done by a larger scale, I don't see a problem for now.