1) That is not a problem of the industry so much as an individual preference.
2) There is SO MUCH official artwork that is so very squicky. There is simply no need to add more categories.
Acceptable arts for submission include but are not limited to:
* Art from sourcebooks
Submissions of art that has been Fixed may be any number of mediums, including miniatures that have been modified with kneadatite to reduce their Squick Factor.