Based on this comic.

I don't judge what people do with their time, even idle time, but I'm surprised there are people interested in loot boxes when you can only get «vanilla» sets. I'd guess any set one want he would have bought at this point. I guess you can farm boxes to get duplicates (which turn into coins) and be ready for when a new bunch of sets are released but talk about commitment! You get peanuts for duplicates and seasonal sets cost triple!

But like I said, free idle time right? Some people just want to game the system I guess.