Old man, he does a good job identifying a problem, not such a good job with solutions. As you say, he has a defeatist attitude towards the exposure he blames otd on. L’maaseh, in homes without internet exposure (of the type he’s referring) there are fewer such tragedies, so I think he’s too quick to dismiss insulation.
ZD, you’re right, the causes in different types of homes are different. Obviously, in a home without internet, if a kid is dissatisfied with frumkeit and disregards his family’s wishes and starts spending time online, it’s very narrow minded to blame his problems on the internet. True, the internet might make things worse, but the key question might be what caused his dissatisfaction to begin with (on that we disagree. You say hats and sunglasses and perhaps stickers on Twizzlers; I say those are scapegoats for a deeper issue, as we’ve discussed).
But, Rabbi Berman’s theory is about homes where internet is accepted, and he would seem to feel that the widespread drop in religious observance, even amongst non Jews, is caused by internet.
The fact that kids from limited internet exposure homes do sometimes leave doesn’t disprove his theory, which is speaking to a much broader demographic.
I suppose if kids from those homes left frumkeit with the same frequency, that would challenge his theory, but it is widely believed that the percentages aren’t close.