Also, a lot of people look at reviews before going to unfamiliar businesses. I don't know about you guys, but resturaunts that have a lot of reviews that are negative are ones that I avoid. Disregarding the negative reviews that mention politics specifically, there are also those reviews that were written by the same people simply saying things like "Came here for an outing, food was terrible" "DON'T EAT HERE"..etc.
Some people arent able to look at things like this and go "hmm...all 1,000 of these negative reviews were posted on 9/10/12..maybe these are trolls". Some people will actually look at it and decide not to go there. That hurts his business.
What business do you know that are owned locally that instantly have 100+ customers on their first day? Negative word of mouth reviews hurt, true or not.