Here is an additional reason why it might seem less useful than it actually is: Maybe the people whose research direction is being criticized do process the criticism and change their views, but do not publicly show that they change their mind because it seems embarrassing. It could be that it takes them some time to change their mind, and by that time there might be a bigger hurdle to letting you know that you were responsible for this, so they keep it to themselves. Or maybe they themselves aren’t aware that you were responsible.
Here is an additional reason why it might seem less useful than it actually is: Maybe the people whose research direction is being criticized do process the criticism and change their views, but do not publicly show that they change their mind because it seems embarrassing. It could be that it takes them some time to change their mind, and by that time there might be a bigger hurdle to letting you know that you were responsible for this, so they keep it to themselves. Or maybe they themselves aren’t aware that you were responsible.