BItter Single Moms; why are we this way?

I admit it. I was a bitter single mom for years. Many years. Why? Because men who don't stop up to the plate make us bitter. Because men who want to be daddy until the relationship sours (whether through divorce or otherwise), then move on to the next woman make us this way. Well, in my situation it was because the (first) man I loved and planned out my wedding and future with told me one day that he didn't think he wanted to get married. Okay, well we have this child and he was a great dad, until he found another woman who he married. After which, his family came first and somehow his 1st born daughter didn't fit into the family equation with his new wife and kids. Okay, fast forward. I have a couple more kids with the same results -- dads who want to make babies but not make families. So, I move on. I stop having kids after number three. I petition the court for child support and I really did move on. And when I say I moved on, I mean with a clear conscious. I didn't badmouth them to my kids, I wasn't trying to be all up in their lives. As long as the child support came (on time), they never heard from me about anything. Once my children became of an age where they could make their own decisions about whether they wanted a relationship with their fathers or not, I let them decide. My son had a good relationship with his father and extended paternal family until his teenage years (when no one knew what to do with him!), my daughters had love/hate relationships with their fathers because they were consistently let down by them. Promises made and broken, holidays passed without visits, games and competitions not attended. So eventually, my daughters came to a point where they didn't respect their fathers and chose not to be involved with them. And so it was, but now I'm bitter all over. My daughter now has a daughter and she's reiterating all of the things about her baby's father that I once said to my girlfriends (and myself) about her father. He uses the baby to manipulate my daughter into letting him live in the apartment she pays rent and utilities for because he "can't bear to be away from his daughter." But this man won't keep a job to provide for his daughter. My daughter finally got fed up enough to put his ass out and now he calls her to say, "what are you doing?" when he should be worried only about what his daughter is doing. He hasn't bought his daughter anything (clothes, diapers, food, shoes) in eight months, and his reasoning is "everybody buys her stuff, she doesn't need anything." I wouldn't say anything is wrong with that reasoning if he was bring anything to the table because they are fortunate enough that so many people love his child that they are seeing to it she doesn't go without. The point of that, though, is so the parents can then use their money to pay bills -- which he doesn't do! Since my daughter put him out, he's living back in his mother's basement not working or paying bills and the child support office is stalling with serving him papers because they can't verify he lives there - with his mama! So anyway, I've held my tongue long enough. It's been 2.5 years. I told my daughter to stop asking him for anything. To stop making him think she needs him because she doesn't. Women have been raising kids on their own for centuries, so it can be done. And she is fortunate that she has an extended family that is willing to help without being asked. But she's prideful (and stubborn) so she'd rather try to make him grow up and be a man and father than to ask her family to help her out when funds run short. I get it, honest I do. I've been there. I think all single mothers have been there. You don't want the people you care most about to know that you've gotten a burden you can't bear... but those are exactly the people in the best position to help you. Okay, enough of this for now. I have school work to do or I'll be a bitter single mom (with all adult children now) who flunks out of college.