Sorry to be blunt, but you fail at logic.
You have a theory about my behavior that might or might not be correct. You have extrapolated that to a theory about all abused children that is even less likely to be correct than the first. You have concluded from that that you see no point in actually trying the experiment and collecting data because it is guaranteed to fail.
Your initial theory about me is incorrect. After years of abuse I got to that point, sure. But I didn't start there. I believe from my own memories of myself that there was a period where I would be willing to try it, and a period where I wouldn't.
Your generalization of my experience (which you weren't there for and know almost nothing about) is even less correct than your initial theory. I was but one child with one set of experiences. Different children react differently. Different children go through different patterns of abuse. My description is anecdote, not data.
And finally your absolute certainty that it is useless to even try is nothing short of absolutely galling. On what evidence do you give up before trying? I've got a heck of a lot more experience/knowledge than you do, and I certainly don't think it is hopeless to try this! (I don't necessarily think it will work, but it seems like a promising idea.)
As for the message itself, well, I am not in a position to judge. Ideally it was crafted with input from people who had suffered the exact kind of abuse they are targeting about what would have been most likely to work for them. I know that the most effective messages are often not what someone without experience would guess them to be. They've got more knowledge about physical abuse than I do.
My experience was sexual abuse, which is different in many ways. But if it shows any signs of effectiveness for one then it can be repeated with messages aimed at other kinds of victims.
For sexual abuse I might suggest a message along the lines of, He says you asked for it, and it sometimes feels good. But it is wrong and you don't want it. We understand. We can make it stop.
Why that message? Because the best way to show you actually understand is to state the deepest, darkest truth of sexual abuse. Which is that abusers try to convince themselves and their victims that this is an act of love, and children are not equipped with the emotional maturity to distinguish "this feels good" from "I want this".
(That message might be a bit too raw. I've known a lot of adults who were unable to look back at their own abuse and face that statement. And explaining it to your kids would be extremely hard. But it is a statistical certainty that they will have kids in their classrooms who are actually GOING through that, but nobody knows it...)