The issue with a lot of procedurally-generated content is that overall things become same-y. Lots of breadth, little depth. When you have a set number of variable sliders, you don't have to see all the possible worlds to get a sense of how many sliders there are and what their ranges are. The problem only gets worse when moving away from planet/landscape generation (dumb matter) and getting into simulations of histor…
Also there is an absence of beauty in the generative/algorithmic-art scene. Much neato, interesting and colorful - which equates to weak. It's HARD to make beauty happen algorithmically. Nigh impossible. Frankenstein hard. Also, the intersection between people who code and people who possess a sharp aesthetic sense is minescule.
Nonetheless, many of the old demo-scene pieces, which are entirely algorithmic, are occasionally beautiful, I'd argue. (A lot of the newer demos just look like music visualizers though...for dubstep songs :/ )