In the old days, feedback was simple: if you didn't like something, you didn't buy it, you walked out of it or you thumped it. Nowadays, it's impossible to eat soup, travel on a bus or visit a doctor without having to sit a written exam when you've finished. Some feedback forms are the equivalent of a GCSE in social studies.
There are times in life when you really don't want to give feedback - for example, when you get into your hotel room, you just want to dive on to the bed with your lover. In your way will be a little cardboard card saying We Value Your Opinion. Stopping to fill it out won't get your romantic break off to a good start.
Feedback generally gives you an opinion with which you are invited to agree or disagree, strongly if you so desire. The trouble with this is that some people naturally feel things strongly, and if they're going to agree or disagree, they'll do this strongly, too. Others feel that strong disagreement is always impolite. With feedback there is an option to say Don't Know or Don't Feel Strongly. This doesn't really cover it, because you can Not Give A Monkey's and also feel that very strongly.
"Other comments" is a section in which you can give opinions to questions other than the ones they've asked. This is where you can put, "I lied about all the questions above." Or where you can make helpful and useful suggestions there, for instance, "Install showers." Good companies will install showers; poor companies will do a survey asking you how strongly you feel about not having showers.
Feedback actually feeds itself, because the one thing everybody says they want more of is communication which, of course, leads inevitably to more surveys and feedback forms. In order to encourage people to give feedback, completed forms are often entered into a draw where the prize is an opportunity to experience once again the service about which you have just bitterly complained.
The media are the worst solicitors of feedback. It's called user-generated content and is virtually free programming. The inevitable consequence of this is that 90% of programming becomes Your Point Of View Has Been Framed. So look out for The Weather: What You Think It Should Be.