I've only seen the UK version, and it goes in cycles of good-awful-good-awful. Being character-driven, when the characters get too quirky, it gets too silly. The more recent ones have been quite good, but quite a lot of them have been unwatchable shiitake. The Christmas special with the stolen meat is still one of my favourite Christmas specials ever.
I think that watching the family protect and enable the father's drinking is only going to go so far. Someone in the family is going to have to draw the line or the viewers are going to become so frustrated they'll stop watching.
It's been on for ten seasons here, so...
His alcoholism and the family dynamics are addressed at various points, but I think that's part of the point of it all; sometimes alcoholism goes unchecked and people still have happyish family lives. It would be too jarring if he suddenly cleaned himself up