I don't know enough to make any character evaluations of either man, but when alcohol enters the picture, it can eat a person alive, and it's always heartbreaking to contemplate. There's a reason the old temperance activists of the Victorian era used to call it "demon rum." If Plushenko has not taken that road, that is indeed one aspect in which he has outdone his old rival Yagudin, and I'm grateful to know it.
I really hope is just a rumour or not a serious problem. Outside the DUI for Yagudin when he was in USA, I have never heard about him having such problems.