If we assume that therianthropy affects (pre-puberty) children and adults differently, it might make sense; there are diseases that do that. Instead of transforming successfully, the children might just be torn apart on their first full moon. That would also add to the hatred/distrust of weres, if children who get infected can't survive it. (This theory assumes that born therianthropes evolved to be in remission until puberty.)

In other words, it makes too much sense for LKH to come up with it.