So if parents separate and one parent is unsupportive, the other parent owes it to the child and other parent to be so also?

It's a slippery slope to start telling kids to care about the forced conformity of their peers. There is a name for it...it's called peer pressure. Ever heard the saying "if all your friends jumped off a bridge would you too?" Why not allow kids the freedom (within reason) to be themselves. Why tell a kid their individual emotional needs aren't as important as conformity. In the future your kids might not come to you for comfort when they really need it and instead will follow the behaviors of their peers. This could be horribly dangerous.