"How is alcoholism less serious that obesity?"
So that's what you think is trivial compared to alcoholism? Fat shaming? It's not. Both are serious. I shouldn't use alcoholism as a punchline, but nor should you insist that you can engage in fat-shaming, or that you can simply assert data about obesity being the fault of the "obese" as uncontroversial fact and get away with it. There's plenty of evidence suggesting that 'obesity' is genetic, there are plenty of thin people who aren't healthy, there are plenty of larger people who are healthy. Size isn't the alpha and omega of health. The fat shaming epidemic, which is pervasive, leads to denial of medical care, misdiagnosis, consumer discrimination, job discrimination, bad-body image which itself causes eating disorders, mental health issues, and a whole host of problems.
The CDC itself has drastically reduced its earlier absurd estimates about deaths attributable to obesity. Fat-shaming has led to junk science masquerading as science. And people eat it up because either they are self-loathing or they think they're better than others based on their genetically produced body size.
I can only say that the main difference between the two, although you dispute it, is alcoholism's (almost always) purely self-inflicted nature and the genetic origins of body size. Also alcoholism doesn't appear to lead to the same kinds of discrimination that fat people have to deal with. For instance (as a just a small illustration), barely anybody talked about GW Bush's past behavior, as compared to the litany of jokes/complaints about Chris Christie's gerth, or the size of Hilary Clinton's ankles (which, as an important sidepoint, fat-shaming and misogyny are closely intertwined). I've not heard of anyone being driven to another form of disorder because of being routinely publicly humiliated for being an alcoholic. There seems to be, and I have personal anecdotal experience with this, a high level of tolerance/forgiveness for the disease of alcoholism as compared to other things. Which is not to say there shouldn't be forgiveness for it.
Also, obesity is not linked to violence, nor is obesity linked to reckless endangerment of the public welfare - both connected to alcohol. And being large is not glorified in society, as drinking heavily is. So there is that aspect as well - it was this point in particular I was reacting to in this instance (foolishly).