Any DECENT father would have his child or children 50% of the time.
Should they also not get into relationships while their children are young??
That would be a tad tricky, given they've usually left the mother of their kids for another woman. Men never leave for an empty bed.
Why don't you go on men's forums and try to lecture them about having their kids 50% of the time, and about staying single until they're a certain age, and about putting their kids first. (Because I see a fuck-tonne more fathers not putting their kids first, than mothers).
I'm reminded of a scenario an older man I dated told me about his single Mum neighbour; the Dad barely took his son, he was unreliable, nonetheless she tried to facilitate the relationships, he arranged to take the boy on a football trip, on a coach with other families to see a match, the boy was excited about it for ages, he was all ready, dressed in his kit etc on the morning they were due to go, *his father never turned up and didn't respond to any attempts at contact by the Mum, the coach left (she couldn't go instead because had another child to look after), she was left with a hysterical, crying boy, kicking & knocking his head off his bunk bed.
Another single Mum I know's ex sees his son steadily oy when he's Dingle, he disappears every time he gets a new gf, at one point he moved a long, awkward journey away from his son to move in with his latest gf.
Thid is not rare behaviour . .this is common behaviour by fathers towards their kids. This forum is chick full of examples.
So don't you worry about single Mums, turn your focus on the real villains of the story.