"tough love" okay, but suppose the child has a mental disorder? Your post makes good points, but there are times, and many where an adolescent is prone to mental disorders, due to the hormones peaking so quickly.
If you know for sure that isn't the case, then I agree with some sort of consequence (sp?) should be dealt with by the kid(s).
And consistancy starting with toddler years and not trying later helps, too.
Take care