There is no sugarcoating it: Lootboxes are very unpopular; especially at the moment. Already they were largely teetering on the edge but the release of EA's Star Wars Battlefront II didn't just tip it over the edge but, rather, gave it an insanely massive shove. There may be no way to recover the practice from this, but why was this one event so massive and disastrous and how much worse did it really make the situation from what it was, whatever it was, before? Well… It's not that easy to tell.
Lootboxes have always been a dangerous game. Spending in-game (hopefully) currency for a set of randomised loot, which may contain something valuable just as much as it will contain something useless. Did you drop 1,000 gems for that nice little lootbox? It may contain the Super-Mega Death Beam, or the Peashooter you already have sixty of. Didn't get what you wanted? That will be either $10 for another 1,000 gems or weeks of in-game grinding (if that's even possible). The odds of getting something worthwhile from a lootbox may be as low as 0.05%... so, that $10 bucks? If you want that death beam you had better be either stupidly lucky or be willing to drop well over $1,000 on the game.
To make it worse, in the games that do offer methods to earn lootboxes in-game, the methods are often slow; easily capable of taking weeks or even months to earn even one lootbox. The result is a bunch of kids running up massive debts on their parents' credit cards for the tiny chance to earn rare weapons or skins, along with adults with no sense of self control effectively working just for the chance to see their beloved character in a bunny outfit.
Why is this even a question, then? It sounds like lootboxes are clearly evil. Well, you would think that, but then you go around and look and see it's not… quite… like that. Basically, while it's clear that lootbox systems exist as a way to earn money, some are distinctly after your wallet, while others are… different. The recent Darth Vader scandal is a perfect example of the former. EA, probably the closest thing to a videogame devil, decided to lock the option to play as Darth Vader behind either large amounts of grinding, or lootboxes. Therefore, if you were one of the many fans of the franchise who also wanted to play as one of the most, if not outright the most, iconic character from the franchise, it would cost you; either in terms of time or money. Likewise, some games like Mass Effect 3/Andromeda will lock things like characters/classes/weapons behind similar systems. Want to use a gun that isn't terrible? Pray to lady Fortune and whip out that card.
However, as said before, it's not quite so clear-cut. In other games, like Overwatch, lootboxes are nowhere near as universally hated. Lootboxes never contain anything but cosmetic effects in Overwatch; you get one every level-up and from a few other sources, and even if you don't get the skin you want, you will slowly accumulate in-game currency, which can be redeemed for a specific item. Likewise, in Hearthstone, while it's clear that the card pack system is a lootbox, many players are used to the notion of how randomised opening up a card pack in real life can be on top of the 'accumulate currency to redeem for the exact card you want' system and a decent amount of free cards/packs. In Fire Emblem Heroes the player can earn orbs for the chance to open a lootbox containing up to five heroes, however, the player can decide in advance which of the five heroes they would like to try to get (a red/blue/green/colourless hero, although exactly which is randomised), they don't have to spend all the orbs and can opt to only summon a few heroes if they want, they slowly get increased chances to earn the best heroes, and the orbs are in ample supply and can be used for other things in addition to summoning new heroes. While some complain, most appear to be totally okay with the system since it means that you can be truly 'free to play' and be on the same footing as other players without having to stress out and work obscenely hard.
However, there is a more fundamental reason for loot-orbs and its related problems. Hearthstone doesn't cost anything to play. Fire Emblem Heroes is also totally free. Battlefront II, on the other hand, cost real-world money to even play and is basically multiplayer only. See a bit of a pattern? Wait, though, as Overwatch also costs money and is literally multiplayer only! Yeah… and the player has access to all heroes right off the bat, with none hidden behind locked doors, and the only reason to shell out is because you have to have that D.Va videogame emote right now! That's not to say that makes it right, but that there is a pattern here even if Overwatch is an exception. Namely, the pattern is this. Predatory games are games in which the only options to get what you really want are to either whip out the card and pray to lady luck or grind for weeks, if not months, for just one shot. Meanwhile, the 'good' lootboxes make it so you can succeed without them, without stressing out, give you ample chances at the free ones, and make it so you are able to do well without having to pull out the card.
What can be done, then? One simple answer would be to outright boycott games that have them, but this is indiscriminate and may block out the next Hearthstone, just as well as it might squelch the next game intent on robbing you blind. Making sure gamers are informed would work wonders, but the people whom lootboxes are designed to take advantage of are often not gamers but casual players who don't realise how terrible the system can be. Banning them, slapping a weekly spending cap, or an age limit could work but would need to be handled carefully at best so that the law doesn't come down on innocent games that don't hold such practices just as hard, or harder, than the ones that gladly run up your debts. Putting a rating/notification system works but, once again, these systems are designed to take advantage of the people who wouldn't care or know in the first place.