If she has two convictions for child abuse and he has no mark against him (legally speaking), if he divorced her he will get full custody.

I'll say it again, the system is designed for the best interest of the child, not to punish men.

It just so happens that men are rarely the primary caregiver so don't have that day to day relationship with their own kids, and as you say, so many of them run wild rather than parent.

In my parenting group, there were 5 single dad's with primary custody, most due to mom being an addict. One was similar to what you're describing. Mom was mentally ill and would not stay on her meds or in therapy.

So, I do have experiencing knowledge, just not personal experience of having to go through the system because when my child's father started abusing prescription medication and refused treatment, I simply wouldn't let him see my child. Eventually, I had his parental rights severed when he started making threats.

You're more interested in complaining than you are in protecting those kids when it comes down to it. You blame everyone around you yet you refuse to act and do what needs doing.