I know it's the most despised response in existence, but RNG is RNG. I actually personally know two people who have had costume drops each with... umm... not 700 hours. Probably somewhere in the 100-200 ballpark each. And the posts on the forums of people with definitely under 200 hours.
I totally get the frustration, but I still contend the point that they are the ONLY real money maker (most people will either only buy a couple stash spaces, or even more cheaply I found out buy only a couple between crafting and hero spaces).
Well, it is despised due to reasons I've stated before and I'm not going to keep repeating. They weigh splinter drops, don't they? No reason they can't do the same with costumes so I don't take it as a valid response at all. They could and choose not to.
I thought Fortune Cards are there as well, are they not? You yourself said they are a "fair" whale mechanic, and as we all know, "whales" are the ones who keep F2P games alive. The few who pay for the many who don't. So now only costumes (fixed price, finite items that a whale can obtain rather easily instead of gambling for them) are the ONLY real money maker? 1 pack makes them as much money as several costumes combined without in fact guaranteeing even 1 costume, so I don't see it.
The truth is, in the end, I don't really care about their bottom line
beyond how I've chosen to support the game, and I don't want to change minds either. The drop rates fucking suck by design. They are not "fair" or acceptable in any way to me, and as a player I am always going to complain about that, whether someone feels what I've paid for the game is enough or not.