The advice is almost always well-meaning, but it’s completely clueless.
“Come on,” the advice goes. “That happened a long time ago. He didn’t really mean to hurt you. They did the best they could. You just need to let it go. It’s time to get over it.”
I know what it feels like to think this about someone, because I’ve done it, too. I remember a conversation I had years ago in which a friend and I mocked someone who couldn’t “get over it” and move on after childhood abuse. That was before I understood my own childhood trauma, so I eventually felt guilty about having said such things about someone else.
But I get it. When you watch someone else go through the agony of long-term pain and anger from emotional abuse, it’s baffling if you don’t have a frame of reference. The person who’s suffered abuse can come across as crazy — at least it can look that way to someone who’s not hurting.

Night of panic and little sleep shows chaos of finding my way
What if a state government shut down and no one noticed?
EU Nanny State bans young kids from evil balloons and whistles
Time and maturity should change what we believe we need in mates
Illegal bribes mean a politician is corrupt, but the legal things he does are just as immoral
Hearing voice of the one you love can be medicine for hurting heart
If parents excuse cheating, what should we expect from their kids?
Love’s closest counterfeit sounds like love but acts like selfish need