Would someone please tell me why the expectations are higher for a SM than a BM?

Why is ok for BM to call the kids a brat, say things like I can’t wait until they move out etc, etc?

How come when a SM does we get labeled as evil uncaring, rotten etc?

It’s not just in here…it’s in life too.

My friend is always calling her daughter a little bitch (she is), and saying she is glad she went off to college, she dreads when she comes back home for breaks, prays she doesn’t move back in after college and does nothing but complain about her behavior, friends, tattoos, etc. This is ok for her to say…..other BM’s join in with their wish lists.

Any time I call my SS a name, say I can’t wait until he moves out, complain about him…I get reamed a new one.
Why is this??

For some reason I am beginning to think that its ok for kids to leave the BM’s home but the expectation is for the skids to live with SM forever?

What is it…BM gets rid of them at SM’s? But when there isn’t a SM involved its ok for the kid to go out on their own?

What am I not getting?