> Often people seem to be happy for other peoples children to do what they like but not theirs. To me this seems like the wrong attitude towards ones neighbours.

I think you miss the important concept, that people can have different world views and different things might be acceptable to them. So I may not approve my kids/family/myself doing something, living some kind of lifestyle, but I accept that there are people who have different values and it's OK for me (as long as it doesn't infringe my freedom, of course).

Otherwise, we have religious fundamentalism.