Here's an art show full of visual work inspired by premium cable. You can buy prints etc. for varying three-figure sums. More traditional fan art, too, is often sold at fan conventions. And I don't expect these folks to get sued. Why is the anti-commercialization norm so strong with fan fiction and video, but not with fan art, and why have copyright owners seemingly tolerated so much more commercialization in the visual field? (This is far from the only example of transformative visual works for sale I've seen; it's just the one I saw today.) Is it the lingering mystique of the unique art object, such that the "original" drawing/painting/etc. seems to have so much more labor value than the "original" copy of a text or vid that a sale of the former is justified?
Also there is no accounting for taste; while my kindergartender couldn't produce any of these, I think my friends do far better work, and for free. Though I liked this Alternate Ending exhibit better, alternate endings being a staple of traditional fanworks, it does seem to me that traditional fan cultures focus more on classic aesthetics--creating beautiful art objects that are also transformative works--than these producers. Intriguingly, the artist who in my opinion does the most polished work in the second exhibit has a Kickstarter for a poster of every Wile E. Coyote ACME purchase during the classic cartoons, and its more widespread success--these ACME posters aren't limited editions of small numbers, like most of the works in the exhibits linked above--suggests that the current art world aesthetic has something to do with avoiding mass appeal. That's not a new insight, but in the context of transformative works specifically I wonder: does beauty make it harder to see transformativeness, or easier? I know in the DMCA hearings we constantly had to say that it was important to vidders as artists to convey their messages in aesthetically rich ways, and some people seemed to have trouble hearing that, even though we ordinarily accept that attractive, seductive, well-put-together art is more effective art.
Of course, I support bad transformative works too! Quality isn't the standard for transformativeness; also you don't get good transformative works without a lot of space for bad ones. But when classical portraiture techniques risk liability for seeming too exploitative of the subject, there's something weird going on about the intersection of art and transformation.