Hey stubborn---
My ex is not an alcoholic. He's an irresponsibiliholic. So maybe take the alcohol out of the equation and just see that this is the way this person is.
My ex left the country for 6 years after our divorce. When he called me (rarely) or emailed me he would share his concern that the kids were resenting him. I'd suggest - "Oh why don't you have a set time to call them? If they knew Dad calls every Tuesday at 8pm and it happened consistently enough I think it would mean a lot to them. Or you could start a letter writing correspondance with them. That would be fun and meaningful!" Like a typical codie- suggesting the OBVIOUS (like does a grown man REALLY NOT know how to "keep in touch??")
Did exH keep in touch? No. Of course not. Yet he still asked (and continues to ask!!!) if the kids resent him for moving away.... no alcohol necessary - just some kind of selfish inability to put himself in a child's shoes? Doesn't matter. I just like to remind everyone that booze is no excuse. Some people (addicts or not) emotionally neglect their kids. Period.
*Sigh*
It sucks. But at least your kids have YOU!! Don't waste your good energy figuring out a definitive answer to why he does what he does. Just decide for yourself. If you think it's alcohol. Fine. If you think it's a character defect. Fine. The sad truth is either way there is nothing YOU can do about it!
Peace-
B.