I generally agree with you but I wanted to point out that the attitude towards abusive parents of 'They were only doing their best' or 'They could have been worse' is called bypassing. It's a form of self-betrayal and a continuation (in your own mind) of the abuse and neglect your child-self experienced.

For anyone who experienced childhood abuse or neglect (physical or emotional), it's very important to have the courage and fortitude to do the hard work addressing the pain. After enough time and effort, the person can hope to get to the place of acceptance, then perhaps forgiveness (although forgiveness is not obligatory).

I've been lucky and brave enough to get to a place of forgiveness towards my parents, but it took years of addressing the pain. Before I was brave enough, I regularly bypassed my own feelings with the thought 'They were only doing their best' or 'They could have been worse.'