They were incredibly closed-minded about any change from the old format, even if it was for the better.
You seem to be forgetting the scenario. Riot split the General Discussion community without changing any of the moderation in the old platform, so both environments got worse. There was very little warning about any of the decisions involving General Discussion, so naturally people felt as though they were being cheated or lied to.
Riot also did very little to help guide these users into the platform, so people's first experiences with the platform were generally hearing people returning to the old General Discussion from the Boards saying it sucked and functioned too much like reddit. Negativity begets negativity, and without intervention from an informed party (Riot, in this case) it just continued to fester.
I'm not saying you're wrong, but the tone of that comment made it seem like you were calling out the GD community when a lot of the problems were actually due to Riot's decision-making. People overreacted, but the dissent was completely warranted.