That's the opposite case, they were pissed that it got banned not pissed that it wasn't being bannedthe council members had to come out and say “don’t send us death threats” when the Volc ban happened.
That being said yeah that's unjustified behavior still.
There was some concern for volc, we can't pretend like literally no one had issues with it, its a mu moth its just meant to cheese some games and be useless other games which I get can be frustrating but its no where near QB worthy, pretty much everyone can agree with that and debate with each other if it actually was broken enough to ban to begin with.
Its not like other mons where its cut and dry 'definite ban worthy' cause it does have legitimate weaknesses, flaws, history, and positive effects on the tier no one can pretend doesn't exist. Even the points that you could argue make it ban worthy can be flipped saying they're actually reasons why its not (volc sounds broken when its running quiver+morning sun+tera ground+tera water+giga drain+tera fairy+tera ice+tera fire+shadow force+fiery dance, but ultimately it can only run one of these sets which actually holds volc back a lot and shows how it struggles in the tier without having to comp around it and specifically target threats.)