"Bothsidesism" is a lie that is used to avoid criticizing one side when the other side is also bad. Just because one side is awful does not grant the other side a free pass to be immune from criticism or to get their way on everything. The idea of "bothsidesism" forces a false dichotomy and then forces you to pick a side, when there are almost always more than two choices. It's what partisans use to beat down people who say "I pick 'None Of The Above,' because you both suck."

You define it that way but that's only you as far as I know - I haven't seen that definition or had that experience - and it ignores the actual bothsidesism problem, which is certainly not a lie IME.