That's because it adds two points of pressure in favor of the World Ideology.
I've noticed something about this that I'm not sure is a feature or a bug or something I don't get about the mechanics
When a civ is only influenced by WI and no other civ, they peak at "civil resistance" no matter how much unhappiness they have. I had Casimir and Bismarck stand at numbers like -29/-59 for a hundred turns. Both went into Revolution and switched only once a civ exerted pressure over them.
That seems to be motivated as much (perhaps more) by hatred of another civ that's picked an ideology as by friendship. In one game I picked Freedom and Russia, hated all over the board, picked Autocracy. England went and proposed Freedom as WI. It passed, yet a few turns after England still my BFF, picked Order as its ideology.... One of those "weird things"/glitches happening with the WC (another: in two games now Bismarck proposes to Embargo CS before he has Banking - destroying the power of his upcoming UB, then gets Banking and tries to have the measure repealed... It makes sense for immersion he doesn't know he's gonna create Hanses before discovering the tech, but in terms of game play this just ruins an AI civ that with the Hanse can be competitive) . I guess the AI isn't programmed to calculate and take into account its future choice of ideology if it has none when the WI resolution becomes available (the choice seems motivated in this case by picking the available resolution that will hurt/anger its worst enemy the most, and to select if it would be Freedom or Order the AI picked the one that would not anger its friend.. or picked randomly any but Autocracy).