No confusion. I'm using "genre" the same way you are - generally. As I said, I'm aware of early examples such as Richardson. I guess I was thinking more of "reformed rake" as a romantic (in the modern sense of romantic) ideal, like in Georgette Heyer for instance. But I stand corrected - it does go further back than I remembered.
As for the rest of your argument, we just don't agree. I will clarify, however, that I don't mean JA is trying to write didactically to teach someone a lesson about rakes. MP is my favorite of her novels because it's complex, and it doesn't tie up in a neat bow as we expect. But I maintain it is realistic.