Not really, it's perfectly reasonable to describe a survey as they did. If I say "59% of Americans are satisfied with their commute", I wouldn't have to specify in the headline that I didn't actually ask every single American.
It's not. The discipline of statistics knows a lot about population sizes, sample sizes, margins of error, and that sort of thing. If you're going to seriously question the fundamental ideas in statistics, there's a whole lot of empirical evidence you need to refute.
> Should an advertiser be able to claim the same immunity?
Have you ever purchased anything that was marketed using statistics? Lots of things, I imagine. How many polls have you answered about those statistics? I'm not really sure how you'd get the impression that anything else was ever the case.