Well, your proposed system, which would let a husband or long term cohabitant "opt out" of having to support a child doesn't really help anyone. Your proposed scenario would allow dads who are dads to 2 kids with a woman (maybe the relationship was great for many years), and then third bun gets in the oven and now the relationship has soured, and well, here ya go, opt out! - So, he's in with 2 of his kids, and out with the third. **** that third child, right? Mom was a **** who had the last clear chance to kill it, and she chose not to kill it, so **** it, no support for her (support to the other two, yes, but not her), and of course, dad will go to school functions for child one and two, but child three, nope, dad won't show up for that. And, when child three wants daddy to help her with a cold or sore throat, or to make taking medicine a little easier, or to snuggle, or play catch or to read a book, or make it all better when one of her little friends does something crummy, etc etc etc -- the first 2 get the dad, the third one, **** her, mommy will deal with it, because that bitch should have aborted her.
Sounds very...... empathetic, caring, kind, liberal, conservative, moderate, progressive? From what milieu does that proposal arise? What is the fundamental philosophy behind this?