Someone who is hurting his mind, body and soul does NOT love himself. Thus if he cannot love himself he cannot love others. Just my two cents from my own small experience. RE excuses, well the alkie I knew also had excuses about everything. Somewhere I learned they are called "Evasion types". Fits perfectly in my book. The hard thing for me was realizing I was behaving similarly, trying to love someone while despising myself and acting against myself most of the time.
Here I have learned what they feel or say is not that important, that you have to push the MUTE button and see the actions without words. Hard exercise for me but there it was- the addict, the alcohol and nothing more. I was not "second" or sharing him with Mr Jack Daniels. Alcohol is all there was and all there is for him.
Gladly the alcoholic is no longer "all I have" and for that I am very grateful.