Its a semi-"nice" sentiment espec for first responders who are constantly called to the same house over and over for accidental poisoning type things... But you also have to take into consideration that there are a lot of things that come into play when you are a teen. Peer pressure, honestly not realizing its a bad idea (your brain is not fully formed when you are a teen) and like Fraggle said - Alcoholism is an illness. And there are normally underlying illnesses such as depression that maybe not be - being managed, or even diagnosed yet.
If a diabetic teen is out with their friends, and their friends are eating a lot of (enter food of choice) , and the teen didn't bring her meter or her insulin and ends up having a diabetic emergency - should she not be treated then because she "should of known better'.
or a kid riding his bike without his helmet falls and has a huge open gash on his scalp and possible concussion - should the doctor send him home still bleeding and nu-monitored because he should of known better and had his helmet on?
What about the 2 yr old whose been told over and over the stove is HOT - no touching! And ends up burning his finger on the range top - he should of known better, his mom told him no, it's hot.. Guess the docs would have to send him and his mom home too without treatment.
Where would you draw the line on who exactly knew better, and who therefore should be treated?