Lighter:
People just want to try to frame the situation in some logical way... and force logic into a situation that defies logic... therefore, they're going to push some blame to the response to abuse - even if it's only a Monday Morning Quarterback attempt to tell the victim "you should've seen this coming and avoided it like the plague".
Another aspect to it, is that people who do have healthy boundaries don't comprehend how in the world someone in an abusive situation got "hooked" into it... don't comprehend - does not compute - how someone would accept abusive treatment in exchange for an illusion of the benefits of a relationship; they have no concept of "enmeshment", Stockholm Syndrome, or even notice the subtleties of manipulation... because they are not vulnerable or susceptible to it. They miss the part about how desperately a person can crave approval, acceptance and how desperately a person can fear even the appearance of "abandonment" - much less the emotional reality of that kind of isolation.
Is it fair? an accurate understanding? compassionate? NO, probably not. But even people with healthy boundaries have fears... and they fear the "tar baby" of the drama, of 'getting involved", of being responsible in a situation that really isn't about them. Even people who do try to "help" draw lines in the sand about how much they'll do... they are afraid of doing something wrong; making a situation worse; or simply don't have the resources - mental, emotional, time, etc - to do more.
I've come to the conclusion after working to the point where I can see my story from the outside - as if it were happening to someone else - that I can't be angry at the people who could've done more... could've intervened... could've protected me. They really didn't have the whole set of facts; had been fed the public version spin of the delusion; and they really didn't have any responsibility to help, you know? The bits they did do - were useful and helpful and represent the fact that these people DID CARE.
There's no superhero who's devoted to righting these kinds of wrongs; no moral court of justice, either. I'm not sure it wouldn't have some pretty negative unintended consequences, if there were. Spanish Inquisition, anyone? Witch trials?
I've also come to the conclusion that my vulnerability to being enmeshed; opening myself wide up to the abuse... the projections and lack of boundaries... despite being "trained" to be this way and not this way naturally... is still my responsibility to fix. I played a very definite role in my own abuse, in other words. I was the patsy, the fall guy, was setup... sure enough. I walked right into the propeller. And it wasn't stupidity that enabled me to do this - it was that sense of loyalty, sacrificing all for those one loves - unconditionally - the damned dependence on approval, acceptance, and the dangling carrot of reciprocal "love" - that made me vulnerable.
Yes, that's right. It was the fact that I understood what the ideal of unconditional love is that made me the "sucker". That got me hooked into the cycle of abuse. And I was volunteering... because I thought it was the right thing to do. The fact that it got used against me, wasn't returned, and eventually turned into a situation where I became "collateral damage"and had to fight for my own life... really doesn't diminish the value of that ideal for me nor does it somehow cancel out the fact that only I am responsible for making sure that I don't get into one of those situations, again.
No one can do this for me; no one else has any obligation or responsibility to "protect" me from those situations. That's my job.
Am I absolutely safe from falling into that "trap" again? NO, probably not. But I've learned a lot and learned how to listen better to my own inner "radar"; I've learned how to protect myself - as difficult as enforcing a boundary can be at times - without going nuclear at every N-counter I have. (Coz I'm the one who suffers the most from those implosions.)
So the Ns of the world are walking free amongst us... unidentified... unmarked. So are psychos with guns. Only a fool wouldn't be afraid, knowing this. But I can't dwell on that or let it stop me from living my life or shrink my life to the point that I never engage with others.
I would miss all the real fun, the real loving relationships, the challenges & opportunities that cosmically offset the negatives of those kinds of people in life.
So... while I agree with you that people often turn a blind eye to reality, and are reluctant to really help - and yes, even blame the victim unfairly - it is what it is. I can't change that. But I can change myself.
The return on investment for that work is quite a bit "richer" than trying to make reality or the world different than it is.