Just to elaborate, the frum world does not have a monopoly on Judaism and as much as you may disagree, Judaism can be expressed in many many ways. Everyone has their preferences, sure, and lines that they WILL NOT cross, but this is the reality. Even within the frum world there are 20 varieties of hat, different psaks on ways of life. The idea of “my way or the highway” – many will choose the highway and not look back.
Re: sending away and removing him from his environment. For me, no rabbi or remotely located yeshiva can convince me of certain ideals that are critical to the frum world.
PS – I am your son, in 20 years – feel free to pick my brain, I may know how he is feeling.