When I subscribed to Consumer Reports I got a survey every year. I always embellished the imports-especially Toyota. If you read by answers you would thing that Toyota was the biggest piece of just ever produced. Never owned a Toyota.
I think it is just as any poll. Ones who have a particular vehicle and have always favored it would give a positive review. Some who don't like a particular brand will denigrate it. I think that may be especially true with the GM twins and their other vehicles. Many still are bitter about the bailout.