I tried Pelican for my blog a while back, and the biggest problem was that I'd forget the syntax of the blog file, and the sequence of actions needed to publish it, if I went more than a day between blog posts. Useful for a professional blogger, I suppose, but not for the casual user. Also, quite complex code to understand, debug, and tweak, compared to the elegance and simplicity of a Flask or even (gasp) PHP webpage.
I have thought, recently, about the possible utility of a dynamic-site generator for things like CMS or even ERP. Imagine you are designing an open source ERP to be customized for different companies. Instead of having sensible tables like "customers", "products", "orders", etc., you have these weird higher-level "table" tables to allow different users to customize their own schemas.
Maybe what you could do to simplify this is create a generator that spits out dynamic sites without the overly abstract data model...