[ghaff]

It probably depends on the survey. If I just want to get out the door of the service department at the car dealership I'll probably give a perfect score unless they really screwed something up. I don't want to explain a non-perfect score and probably shouldn't give one so long as the experience was "OK."

On the other hand, like many, I probably tend to follow something like the XKCD star rating levels (https://xkcd.com/1098/) for products. And for employee surveys, I generally answer somewhere in the mildly positive range to most questions.

I'm not sure I've ever answered an NPS survey but, for most companies, I'd probably be somewhere in a similar range, even for companies I'm perfectly fine with most of the time.

The more complex the transactions/products the more reliably you'll have areas of gripe-age. A book or movie is rarely 5 stars for me. A USB cable pretty much works or it doesn't.