This discussion seems to be addressing people of a certain socio-economic status. Perhaps my view is biased because I have spent most of my career working with couples in conflict and domestic violence. The age ranges from early 20’s-mid 30’s, lower socio-economic status. Cheating is the most pervasive problem I have seen hands down. Both genders do it. Phones and text messaging are a particular source of conflict. These couples have loose boundaries, lack of communication skills, and are generally chaotic.
My guess is that the demographics being addressed here (white, middle/upper class, mid 30’s and up) have better communication skills, more appropriate boundaries, and in general, live their lives with less chaos and drama. That said, they are probably more sophisticated about hiding the infidelity (Desperate Housewives comes to mind). Thus, it goes unreported in social circles. I would hypothesize that the lady in this article is divorced because her husband was in fact, cheating.