Morally reprehensible, vile, evil child abusers.
Likely it is more about a self serving desire to be noticed and garner some sort of social recognition at the expense of their child’s well being.
They should have the child removed and both go to trial for abuse of a minor.
I think you've hit the nail on the head. Take a look at photos online. Many are selfies. Many folks have turned into narcissists, and selfies are their way of letting others know they're "special". Trans-ing their children is just one more way to show others that they're cool, they're hip, they're special...just another merit badge on their sleeve. In reality, they're broken people causing more harm than they can even remedy.