I don’t believe that the term ‘generic’ had much meaning when you are discussing authors and writing.
Some of the best writing ever can be described as generic, cliche, and any other term you can think of that describes themes and characters that have been used so much that they can seem overused. Consider Shakespeare. His plays are absolute cliches. Totally generic.
And still, they are fantastic as are the themes and characters of many similar stories. Because ‘generic’ simply means ‘usual’ and describes the human condition, which is what most writing is about.
So it’s not what’s generic and what isn’t, it’s what the author does with that generic, commonplace, normal, cliched story.