I understand what you are saying and I also understand where your son is coming from. I'm only 20 years old and have diabetes and not long ago I used to not have a care in the world. Go eat alot of pizza or sushi with my friends and not take my insulin until one day I hit rock bottom. I ended in the hospital with BG levels up in the 500's-600's. It's sad to say but young people like myself sometimes learn from self-destruction. Everything my doctor, mom, dad, and grandma would say to me would go in one ear and out the other. I only know one other diabetic that's the same age as me and he did the same thing. Did what he wanted to do until he ended up in the hospital. Some young people have a trigger that makes them straighten up. Mine was having a touch of death for me to get my act together. I'm slowly working on it, but talking to people up here helps a lot. I feel like I'm not alone and this isn't as much as a cruse as I thought it was. If he ever just want to talk it's plenty of young people online that's going through the same thing that he is.
This must be very frustrating and frightening for you as a mom. Unfortunately many young Type 1's I've spoken to have gone through this kind of phase as teens or young adults. It's normal to feel you've been cheated by being given this condition and to want to be carefree as your peers. Unfortunately as you know, this can be very dangerous. It is not just the longterm complications but the real and immediate danger of DKA.
As with most things during a certain developmental stage, some young people will confide in just about anybody BUT their own parents. One thing you might encourage him to do is connect with other Type 1's his age. I'm sending you a private message with a url for a message board that has a lot more traffic than this one and lots of young people who are very positive and successful in their diabetes management. Best of luck to you.