You give people too much credit. And I don't know about you, but I wasn't aware of Larry's behavior while he was a coach here, at least to the extent that he was an alcoholic.
Substance abuse and addiction is usually related to some other type of problem. People don't just decide to become alcoholics for the fun of it.
And a lot of those people also don't have the support and resources to get help, because of friends and family who blame and judge them instead of trying to help and understand.
If a soldier comes back from war with PTSD and starts drinking heavily to deal with it, I suppose he isn't diseased either.
I've actually heard a lot of stories about Larry's behavior - some of what he would say to the players, and other times when he was embarrassing in public settings (see also: the bar) after games. He'd say things not becoming of a coach about the team.
I realize people don't usually just decide to become alcoholics just for the fun of it, but Larry had endless resources. He's not a homeless soldier with only a VA card. He had millions of dollars a year in income, and a university that was very supportive of him.
There are large numbers of resources for ANYONE who has a problem, regardless of their income. That's why we have Medicaid and other federal programs - go to the ER and get checked into the hospital for long enough to detox, and then use one of any number of free programs to stay clean. It's not just as easy as that, but the resources are there regardless of your income or support system.
In your example, the soldier's disease is PTSD, alcoholism is a byproduct of how he decided to deal with it rather than seeking help at (again) any one of the programs available to a vet. Not everyone who has PTSD is an alcoholic. Others choose to deal with it in a way that doesn't rip apart their families.