##Edit: Even if you disagree with the reasoning below, don't downvote me too much! I want more people to see our honest response to this question.
This orange essence thing is a spicy one but I'll take my best shot at addressing it. The most honest answer it comes down to is that we wanna be able to spread out orange essence type loot and rewards across multiple systems without having to take an additional huge revenue hit at the same time that we're making runes free.
I'll explain what I mean.
Basically, when we first started giving out skins and stuff through the loot system, the only way you could get it was by
- paying for it
or
- earning it through the mastery chests.
Going into 2018 you're also gonna get skin content through things like events and honor (lets call them "orange shards" since we're really talking about anything that can be disenchanted into orange essence). We lowered the disenchant rate on shards, and we're giving out more shards.
So that's what I mean by spreading it across multiple systems. I think we'll actually have to wait and see whether players feel that the additional shards from the other systems make up for the disenchant rate changes. Preseason shipped with some other upgrades to loot like bad luck protection and chances for double drops in chests, and I think we'll have to wait and see how that feels for players before we'll know.
Now, there's another question implied here, which I think also bears addressing: "Why can't Riot just give us more orange essence and more shards?"
The answer is that we make money on League through RP sales, and we want to be really responsible about how much we cut into RP sales when giving away stuff. Giving away skins and cosmetics through our in-games systems is something we have to manage really carefully—if it becomes to easy to earn orange essence and shards, RP sales would go down a lot (why pay for it when you can just get skins for free?). Even though League is free to play, we do need to make money and manage it responsibly so we can reinvest it back into the game. That's why making cosmetics too easy to get for free would be irresponsible for us, as a business.
I know it's hard to get excited about an explanation like this, but I hope it makes sense!
##ONE MORE LONGISH EDIT TO CLARIFY A POINT:
I don't want to make the promise that the orange essence amounts you get will “even out” or be the same as before. There’s way too much variance in the rates that people get OE from mastery and all the other systems for us to say that with a straight face. And the truth is the nerf to OE disenchant rates was significant.
It’s more than we reigned it in to give ourselves wiggle room with these other systems. And honestly, the revenue hit from making runes free was a factor we considered as part of that. The goal is to make rewards systems that feel meaningful, rather than just constantly increasing the amount of stuff we give out every year because player expectations keep rising.
It feels icky when we start talking about protecting revenue and budgets and shit, but we’re open to feedback on this stuff. I see basically no one talking about the double drops or bad luck protection that we already added to the system, so I wanna wait for a while for people to get used to the changes.