These are certainly important points/observations. Here is an excerpt from Charles Thomas Samuels' interview with Robert Bresson (Paris, September 2, 1970). Full text is available here.
Samuels: Until now [Balthazar], all your films take place, as it were, without spatial or temporal particularity. Here, for the first time, contemporary mores are unmistakable: the blousons noirs, jazz, etc. Was this conscious and deliberate?
S: It just happened? Yet it happens again in Mouchette and in Une Femme douce. For example, in each film jazz enters with such volume and cacophony that it becomes hateful. Am I not correct, then, in sensing, beginning with Balthazar, your hatred for the modern world?
B: Perhaps not hatred, but rather distrust for some kinds of modern society. I am starting to write a script about the forces that dominate modern man.
S: What causes this recent interest of yours in contemporary life?
B: This interest is not recent. Since my balms have become simpler and simpler, I want to attach myself to some material that is resistant and that will make my work tougher.
S: Do you think it is a reflection of your time of life: the impulse to judge the age?
B: No. I don't judge; I only show, Or rather, I show how the world makes me feel now.
S: You say that Balthazar must pass among the vices of man. But Gerard, because of the very accuracy with which he is portrayed as a contemporary juvenile delinquent, seems to me to be too banal to represent vice.
B: Since six years have passed, he may seem banal. In any case, he is imbecility and violence, which go well together, the one producing the other.