I too have a problem with so many stories whose cause is the controlling DIL. I also find it very interesting that it seems to be the DIL (and not SIL) so often when I read stories.
Those the article on verywellfamily.com may explain this phenomenon:
"In a conflict, males tend to employ a "fight or flight" strategy, and family conflict often results in the "flight" option, meaning that males often withdraw from the conflict. Because the male refuses to engage, the estrangement tends to be long-lasting and intractable."
www.verywellfamily.com/breakdown-of-family-estrangement-1695444#statistics
The stats I have seen often, though I don't have a study available, tends to skew towards parents not seeing a problem before estranging vs, EAC reporting there was, and they brought it up only to not be listened to.
I can offer perspective from the EAC point of view. Of course each case was different, but hearing from EAC provides a different perspective, all of which make sense and does not = controlling DIL/SIL.
The most often reported reason I see from EAC is that once they are adults and on their own, they meet someone and learn and see that what they believed was a normal family life was anything but. Or they decide that the life they grew up with doesn't suit them now. Recent example: politics.
Of course we also need to bring up the fact that are 2 entire generations of people worldwide who are pointing fingers at each other and calling the other narcissists. And both generations believe they are correct in their assessment.
It is easy to blame the outside person on estrangement. But the question I usually ask myself is this (especially for parents of sons), how is it that so many of us raised men who are so easily brainwashed? I know that sounds harsh, and I don't mean it that way, but it is a valid point. Why are so many SONS being led away from parents? Are we raising ours sons to not stand up for themselves and make decisions on their own? That just seems so strange to me. And if this such a common problem, why aren't we putting these women in charge of running the world? Because apparently they have some type of superpower.
Or maybe it is the fact that the son made this choice on his own and it is easier to blame the DIL? It is a totally human thing to do to protect our brains from hurt.
I also want to address the point of seeing SO MANY people say "I know these people and I couldn't never imagine what they did to be estranged. They are loving caring people who would never do anything wrong"
Says every person who sees someone they know be arrested for domestic abuse, or sexual assaults'. Or hears about affairs, or theft. My point being that we do not know what happens behind closed doors. Every day what we consider normal, caring, loving people do things they shouldn't. So why are we judging people by appearance? They "LOOK" like such normal, loving, caring people is like judging a book contents by its cover.
People think my own abusive mother is an amazing, loving caring person. Except they have no ideas what happens behind closed doors. And abuse is not only physical. Some EAC who were emotionally abused wished it WAS physical because then people would see the truth about these "loving caring" parents.
Again, neither here nor there, just a discussion as I like to have. Each estrangement story is unique. But I do hope that this brainwashed child thought process starts to subside. It is either not as big an issue as we want to believe OR we need to start raising our children differently because it is something we must be doing to result in so many people who are capable of brainwashing another or being brainwashed.
I want to say I am not saying all parents are abusive nor am I saying all children ARENT abusive. But hearing various thought processes is what brings about change in certain situations. If neither the EP nor the EAC look inward and insist they are blameless, there will be no forward movement.