Adults with unresolved issues of their own often project those issues onto children in their lives or that they see around them/know of through media, and while believing that they are advocating for the children, are actually trying to vicariously heal whatever damage they sustained themselves.
It’s a narcissistic approach in that on a fundmental level, they’re incapable of seeing the child concerned as a separate individual with their own unique experience, personality and needs, but only as a kind of extension or reproduction of themselves.
As you say, they “lack the ability to critically reflect and centre the needs of the people they should be supporting.” And not just the ability, but the will to do so, too.