As opposed to what? JD Powers seems to do the same. If you have a better survey with more rigorous standards that actually has enough data to by useful and comparable across many cars and years, I'm all ears.

Here's what both Consumer Reports[1] and JD Powers say about how they collect their data.

1: https://auto.howstuffworks.com/buying-selling/consumer-repor...

2: https://www.jdpower.com/faq