That is a tough comparison. Driving drunk prohibitions are enforced because it is dangerous. Public intox in not nearly as dangerous.
Put it another way, it is the same category as profanity or dress code. It is also open for personal opinion. Public intox people that are giggly and clumsy and not cussing, puking, or being rude are far more 'classy' than people using profanity, cutting, spitting, wearing tank tops, flip flops, tacky t-shirts, or... the list goes on.
Of course add inebriation to all of the above and yes, I admit, you have a social cringe fest on your hands.
I don't drink often at WDW, but when I do, there has never been a 2 drink minimum. I typically have 4+. And no, I don't start cussing, stripping, or other obnoxious behavior. ...other than smiling absolutely constantly. A trained eye could probably tell I am tanked, but most cannot.