Why are women out here making excuses for their useless partners ?

Could be loads of reasons
If your partner is shit and doesn't care about you enough to help you, there is almost always an element of DV (coercive control, verbal abuse)
Lot of sahm experiencing financial abuse
Could stay together for the kids
Could simply be unable to afford to leave and women don't want to leave into homelessness
Cultural or social pressure to stay together
Don't want to be a single mum
There's a huge perception that most men are the same, and leaving one bad relationship is likely to mean either another bad relationship or being single forever
Husbands often do not pull their weight but they do more than zero, which means leaving makes you worse off
Might not trust him alone with the kids so don't want to leave and risk shared custody