I'm not sure I manage to follow accurately. If you don't save the art you make then it's gone, generative or not. If you do save the output in some way (either by saving the output itself or saving the full information needed to regenerate the output) what is special about doing so on the blockchain vs anywhere else beyond the aforementioned proof of ownership?
One is of course allowed to care about proof of ownership and the method used to do so if they like :). I just didn't follow the response in context of the question of how it's different from doing the same without the blockchain otherwise.
Unrelated: Kickass you're the Monokai author - I still use that today! Have you ever posted a retrospective about Monokai?
A generative system can produce an infinity of outputs. An art platform combined with a blockchain allows you to store a finite number of outputs from the same system definitively without knowing upfront what the outputs would look like. This forces you to think carefully about your system: it should produce interesting works with each iteration. Some people call this long form generative art.
Regarding Monokai, I’ve written some history about it here: https://monokai.pro/history :)