Kids make their own money: allowance, part time jobs, as gifts for bday/xmas. Funds can be loaded to an account using pre-paid cards. You can also order just about anything online these days using your debit visa card or xfered from a bank account to a paypal.
Parents don't buy kids handheld games any more. Money that would be funneled into nintendo products when we were kids are now just directed at mobile apps (since parents these days all give their kids a cell phone by age 8 because they're afraid of kidnappings or something). There's a large exposure when every kid has a smart phone.
The article talks about how he had a job and earned his own income. His parents tried to sever his Internet connection but he still played over his cell network. The parents identified a problem - they could not stop a free-willed individual from doing what he wanted to do for the same reason you can't tell a depressed person to cheer the fuck up.
I don't want to blame anyone else? Your entire contention is that parent's should do something. OK... did your parents control you when you were a kid? Did you not watch R rated movies? Drink alcohol? smoke? Your wonder solution exists outside of reality. Kids don't handle situations as mature adults and mature adults can't control kids 100% of the time. The timeframe required to make a digital purchase is instantaneous. It's easier to get away with as a kid than jerking off to porn. You can try to stop it but as time passes that kid is going to get older, smarter, make more money, become more independent... I think you and I may be able to impart wisdom to a child between the difference of what is OK to buy and what isn't, but what of all the parents who know nothing about the industry? Non-gamers who can't tell the difference or identify the minutiae of spending on games?
I've made the point that I don't like the idea of a randomized loot box. Has nothing to do with EA. I don't play HS or OW because those games are just designed to sell you MTX. "Content patches" are just MTX patches. They produce it to print money. You say your fine with cosmetic loot boxes; so as a parent you'd be fine with gifting your child HS packs or OW loot crates? Do you not feel that you're exposing them to a gamble mechanic? The kid in the story (the one you've responded to twice and still haven't read) had a cavalier attitude; being a teen, he didn't have anything else to spend his money on and didn't seem like a big issue. Looking back on 3 years he had spent $13k with nothing to show for it (an extreme case but still, what limit IS acceptable?)
Loot boxes are designed to entice you to spend money to obtain an item without giving you that item. It's predatory. Like Zomnivore mentioned; there's no upper limit to what you can spend and these companies exploit that. And there's no end to the content you can purchase. New 'harmless' cosmetics are always on the forefront of content development.
I write all of this to give context to my point of view. Did I change your entire opinion on the matter? Did I sway you with all of my reasoning and examples? No? So how can a parent 'do their job as a parent' and tell a kid not to spend money on micro transactions? This is why problems like this exist - It's not for a lack of effort or responsibility.