The OP has defined everyone to be non-faithful and then asked, “Why is no one faithful?” Well, because that’s a silly definition.
One might note, for example, that no one really likes to dance. Does anyone dance 24 hours a day? Do they replace all their joints with a ball bearing and a minimalistic magnetic cup, so that their limbs can all freely rotate through an inhuman arc? Do they wear implanted speakers so that there is music playing right into their ears without pause? Why do you think there is such a dearth of true dancers?
Maybe some aspect of life is enjoyable in it’s purist and most unrelenting form.
But I would suggest cycling through some activities in your head and trying to think of one that you can’t attach the word “too” to, and come up with a scenario that would explain the “too”. Can you even think of one where you can’t succeed? I mean sure, most of those will be silly, but likewise it’s silly to suggest that there shouldn’t be obvious excesses of free marketry if it’s a good thing.
The point being, though, if you can’t think of an activity that is “too” proof then how reasonable is it to expect that anyone would embrace purism of free marketry and not be a lunatic? How reasonable is it to think that the ability to envision a “too” case means that the activity is bad?
If you did find a person who was attracted to my definition of dancing purism, that would be a crazy person. They might exist, but they’re not going to be someone worth mentioning as “a person who really loves dancing” except as a cautionary tale.
But having found that one “cautionary tale”, have you actually learned something? Because nutball dancehead exists, should we really be scared of dancing?