The drunk driver situation adds an element of risk of harm to others, and that can justify intervention.

But to stop a drunk adult rock-climber also seems to violate the basic principles of human self-determination. Even society as it is today with all its compromises doesn't interfere consistently with adults who engage in extreme sports.

My intuition remains that I am justified in coercing my 12-year-old in that situation in a way I would not a 25-year-old.