I've always thought that a natural 'friend library' for libargs or libopts could be produced which parses the args and creates a dynamic gui from it .. but now

I've always thought that a natural 'friend library' for libargs or libopts could be produced which parses the args and creates a dynamic gui from it .. but now I look at this and wonder, why hasn't someone done this already? It seems like obvious low-hanging fruit ..