Do you test it each time someone claims that it's flat? I doubt it.
> Why are shame and insults fair game for flat earth but not Christianity
Where have you been living the last 50 years? Christianity is absolutely fair game, at least in the West (or maybe the Western West? you'll have different reactions in Poland). Best to reach for Islam if you want a religion you're in theory allowed to make fun of but not in practice. But even there, it's not society that punishes it, it's a small number of extremists that the mainstream tolerates for political reasons.
And you're not allowed to criticize capitalism? One of us really must've jumped dimensions recently.
> Everyone is ignorant in many ways.
But it's not really the same. There's a difference between "I have no clue how DNA works" and "gravity does not exist and we're just not falling into space because the government has people with invisibility cloaks holding us down".
And your point isn't even relevant. Scientific facts and politically charged events aren't even remotely the same when it comes to ascertaining truth value. Never in history has there been a war where only one side spews propaganda.