I dont know what sample-size you are looking at, but i got my wings on 75(~50bucks) and my friend got it in 100. RNG boxes are RNG, the company are not supposed to stop your addiction to gambling nor should they, it's your own fault if you don't want to stop. It's easy to say its somebodys else fault instead of thinking first about yourself and your exspectations.
It's hilarious to see that f2p-players who don't want to support the game want everything that is ingame, i expected the event to be more cash-related and it is. It gives some decent value and the big "crits" are the costume and wing. People buy a tiny amount of boxes and expect to get the big crit. That's not how it works, and neither in B&S which a few ppl mention here. I'm pretty sure if you don't spend a lot of keys you won't see the big crits either, since i play this game too. I have used 300 keys, which is the equivalent of 75 bucks and i didn't got anything. I know some ppl who open like 4000 keys in there and don't get the big crit(60 oils), stop mentioning other games that are probably same or worse. I have seen games that went under because devs keep listening to people who know nothing, making the game easy and equalized and ending the game. Live with the fact you can't get everything every time.
TLDR:
You buy a tiny amount of boxes, expect to get the big crit, you don't get them and blame everything else.
Then you give in to your gambling addiction, buy more boxes than you should and end up frustrated.
Expectation are the keyword i want to mention, you knew yourself that they will be hard/RNG. Still you can still get them since they are tradeable so yeah. Gonna peace out, forum discussion always end in a negative note since, nobody wants to admit themselves they were to greedy/conceited of getting the stuff.