Shouldn't parents be aware of what their children are playing? Supervising them, telling them to get off the games when it's time to do other things.
All parents have to do is limit their kids usage of games. No different than when I was a kid. It gets to a point mom and dad say enough and go outside. Parents lack balls now.
As for the additional shit storm of kids going ape shit buying mtx, simple solution. Just lock the credit card behind a passcode. Or just delete the card info from the account. If the parent gives in and buys Timmy some mtx, manually enter the CC info, but dont save it on file in case Timmy figures out how to buy shit on his own or finds out the passcode.
How that is so hard to do who the fuck knows.
I never save my CC info on sites and I dont even have kids. For me, it's more about potential hackers. And for Xbox dollars, I just buy preloaded $$$ cards from Costco since they are 10% off. Even if a hacker got in, most he gets out of it is maybe $50 at any given time.