"Why doesn't riot respond?"
TL;DR: It's risky and miscommunication is worse than no communication from a business standpoint.
Communication with a game community is something that is rare and highly valued. Many companies are completely shut on how they communicate upcoming changes, what they are looking at in upcoming changes, how they are going to address current issues, and what their thoughts are on current issues. There are also companies who are somewhat open and communicate with their communities. It builds trust between the community and the dev when they promise something and follow through, it gives the community some sort of idea of what is going to come in the game, and can lead to the community contributing in the balancing of the game.
It's also a huge double edged sword. One thing that Riotblahblah said 2 years ago now gets blown out of proportion and people start screaming about how terrible the company is. Meddler says "We are looking in to nerfs for X" and 5 months later after the champion has fallen out of and back into meta people start screaming about favoritism and how they were supposed to be nerfed 5 months ago. Communication is good, but it is also dangerous.
"Why should they care if people are upset! They should just stick to their word!" Well yes they should stick to their word, but it's a lot more complicated than that. Riot is a bunch of individuals, not one sentient mass. Every employee has a slightly different idea on what is going to happen with upcoming changes. Maybe X rioter missed the last meeting because they were sick and didn't realize that that balance change was called off. Maybe X rioter just used bad wording or accidentally sounded too sure of a change going through. Maybe X rioter agrees and is planning to try and bring up nerfs for Y champion but the changes don't stick at meetings.
"Why does riot even care then? They're adults who should have thick skins" It's still incredibly demoralizing to know that large groups of people vehemently despise you. It can make your company look bad if there are "tons of examples" where the company "lied".
"riot never responds to gameplay posts but frequently responds to memes." This is pretty obvious. It's a lot harder to extrapolate a balance change from "Haha, I always feel this way on X champion" or some sort of response gif than "We will look in to making this change" or "Changes for X are on the table"
it's pretty dang obvious why they don't respond often to balance posts. That's not even mentioning the number of people spamming for nerfs for X on a completely unrelated thread.
