I think Ozzy's shown the typical signs of being an alcoholic for years. Those shakes might be a sign of parkinsons, but there is a lot more alcoholics and addicts in general who suffer similar type shakes especially when they are breaking the habit.
Imagine all people just gave up like that dickhead suggests. Doc: "You're sick, you should see an expert who might help you deal with it." Internet expert: "Nah don't waste your time, I've seen people die, you will too." Patient: "Well doc I understand you're trained, the expert is trained and educated, but honestly I think the internet has this one covered."