An important thing is the pacing and writing. Some games have to much talking and it makes you want to click to the good bit. Also the amount of words there are in the text box. Should be max 3 sentences.
I agree with OPs view. It's something about the dynamic of ugly bastard and beautiful woman. Something like opposites attract. Black and white, Ying and Yang. I just don't want the ugly fatty taking up most of the screen and blocking the view of the woman.
It's nice to see that the female characters didn't mutate unrealistically large breasts as they grew older. Not common to find games where the adult females are on the natural or flatter side.