Because it evidently does not self-regulate. Otherwise, 2017 wouldn't be the year of the lootbox, with basically every big name, full price release being stuffed to bursting with them, regardless of the damage they do to the games themselves. Lootboxes are fun, I'm in no way objecting to that. But they're fun in the exact same way a casino is fun. And there's a reason we regulate that to fuck and back: because it's inherently predatory, a not insignificant portion of the population is fundamentally incapable of engaging with it responsibly (be it because of immaturity, addiction, or simple lack of self control), and it's existence benefits literally no one but the asshole fuck who siphons money out of the people who engage with it. There's plenty of ways to leverage randomness and the psychological rush of gambling in games that aren't ludicrously predatory. Just make the lootboxes earned via gameplay, or make game challenges reward loot or any of a million other possibilities, many of which we've spent the last thirty years perfecting. The second you tie real money into it though, you've gone too fucking far. That shit needs to be regulated. Maybe not banned (though I would honestly prefer that), but at the very least it needs oversight and consumer advocacy. I've seen way too many people (and personally known two) utterly ruin themselves, spending hundreds of dollars they didn't have on this kind of shit, to ever shrug it off as harmless fun.