Because in the many decades they have been doing this, no one has come out and said that CR is skewing the results. No one from any car makers corporate offices have come out and said it. This isn't some conspiracy.What's not to say that many car owners are not affiliated with certain brands that have an agenda to push it to the top of the list?
How does CR obtain this data? Surveys, there is no other explanations.
What's not to say that certain car manufacturers don't pay consumer to positively report on these surveys?
And anyone who thinks Toyota's legendary reliability is a myth clearly has never owned a Toyota long-term. They invented lean manufacturing. They perfected six sigma. They still keep up with those methods, and will always do so. They are the best in the industry by a wide margin, and have been for almost 40 years. Next time you see a tow truck driver, ask him how many Toyota vehicles he has towed due to them breaking down. Don't be surprised when the number is equal to or close to zero. Toyotas don't break down. They keep going until they get totaled in an accident, or junked because someone wanted a new one. I had a Toyota Camry for 15 years. Drove it 180,000 miles. Never changed any fluids besides the oil, ever. Drove it 10 miles without oil once. I treated it like crap for a long time. Got it up to 130 mph once because I was a stupid kid. My total repair bill for that car over 15 years was about $500. Got rid of it because I messed the bumper up and wanted something new it still ran perfectly.
Other cars can be reliable as well. But no one hits a home run nearly as often as Toyota.
But honestly, feel free to believe what you want. The more people that think Toyotas are unicorns, the cheaper my next used Toyota will be.