People only get upset at grinding, which has to be a thing it's how stories are told in games - put yourself up against x content for y amount of time for z result, etc, - but what's happened is a new normal where the result is a loot box which may or may not give the result you seek, so people feel burned. Rather than the player killing 10 goombas for a green hat, it's kill 10 goombas for the credits that unlock a shot at a green hat - or just buy credits. It's a way to skip the grind. Without grind there's no reward. Both the mobs of negative the internet forms against devs, and publishers pushing this model is creating a conodrum where it's hard to create proper game design. D2 has been gutted by this mentality of satisfying players who are only willing to play half an hour or give a mission one attempt, but expect to be end game WoW decked out. Publishers saw this gamer and figured out you have money and will spend it to get the content, if not it wouldn't have reached such a head.