Is it that they don't allow the sixteen year old you are talking about to do whatever they want (therefore according to you/them they don't care about their children), or is there something more to it?
Also what qualifications have you got to criticise them - have you been a parent, do you know the stresses placed upon them in Western societies, where according to the law their every move may at some point be described as "not in their child's best interests?
Couldn't a little metaphorical knocking of heads together do a lot more for all concerned than running away to what may be a worse situation?
Something for you to think about there perhaps from a father of an estranged child (excluded because the mother wanted it that way though).
Graham