This is such a fundamental, but grossly overlooked fact. The spectrum implies that a tether to one ideology (and therefore party) means a tether to all others that fall under the umbrella of that party's stance. The other side is either 'evil' or 'stupid'. It fosters polarization and a basic disrespect for the legitimacy of other people's thought and opinions - this is harmful because it creates a pendulum effect in the cultural narrative and gives rise to extremism on either side. Moderation is underrated.