I don't agree. Children are special in that there are several psychological effects like baby schema, innate caregiving response, etc. which one would have to overcome. Seeing children as younger versions of adults is a very technical view which I'd be surprised if it was in any way prevalent.

You're absolutely right in that a text-book racist might not distinguish between children and adults. Imagining that this is so common it dictates decisions on this level is hard to grasp for me.