The characters are described as beautiful yes but would they resonate with all of us to the extent that they do if they were weak or lacking on the previously mentioned qualities.
I think it goes without saying that anyone who has fallen for Book Jamie has done so because of who he is, not what he looks like, because books aren’t a visual medium. Meaning, the author tells us that Jamie is deeply attractive, and we translate that in our heads to whatever our personal version of attractive, tall, well-muscled, red-headed man is. There’s not a whole lot of leaping to make there. It just happens.
Contrarily, because TV is a visual medium, attractive actors must be hired to fill the roles of attractive characters. Now there’s a whole lot more room for disagreement because my version of attractive might not be yours, etc.
But back to the books, I would argue that what makes Jamie and Claire such compelling characters is the way their personal characteristics make them weak, rather than strong. Jamie’s honor can hamper him at least as much as it elevates him, and Claire’s unbending tenacity (particularly when it comes to her calling as a doctor) gets her into all kinds of trouble, right? And it’s the ways they help each other get out of those situations that create a picture of a beautiful, if imperfect (and therefore ultimately human), relationship.
Here’s a question: Which character do you love (or appreciate or relish or whatever) more, Jamie or Claire?