Hello. When I drank I think I chased away anyone who was close to me on purpose just so I could be alone in my misery, or at least away from people who looked down on me. I was living a party for 10 years or so and if you weren't interested in my drunken psychosis behavior then you were a pain in the butt to me.
It sounds to me like he is mentally being entertained by the alcohol now and for many years. If he is okay with it and accepts the terrible relationships then he may never quit.
But I hope he quits for his kids sake so they can see their dad sober again. Life moves along so fast and with alcohol sneaking up and biting you like a snake health wise there is no time to waste. He either quits or drinks to his death.
It all sounds like a sad situation and I feel sorry for all involved. And yes it is selfish. Alcohol trips out the mind and puts people who abuse it in a different dimension. Their world becomes rebellious and if anyone gets in their way they stomp them. It's as if alcohol is a substitute and a better one than that of other people's love.
I wouldn't doubt it if he feels inadequate in many ways and chasing away people is an act of relief so he doesn't have to face those facts. < -- Just saying I felt this way at times.
Take care.