The problem is that alcohol is his solution to dealing with the world. Until he accepts that the consequences and his life are totally unmanageable and that he is unable to stop once he has "just one" drink and finds a New Solution, he will continue to drink.
No, it isn't an excuse, it just is this way. Hopefully he will find a solution (AA's 12 steps work wonders) to replace his drinking.
I wish you well! I hope he finds recovery.
Peace, love, and hugs,