Taken literally, a FAQ document does what it says: it provides the questions that are frequently asked in a Usenet newsgroup
(or some other forum) or about a specific topic, and provides an answer that summarizes and clarifies the actual discussion surrounding the subject.
Its purpose is to diminish the recurrence of the same discussions over and over again.
As a FAQ author it's hard to keep your personal interests and pet peeves from shining through. This isn't bad as long as the questions and answers actually represent the recurrent discussion correctly. Sometimes you see a 'FAQ' that doesn't even attempt to do that: it lists those questions that the author wishes readers would ask, and the answers that the author wishes informed readers would provide. This danger is particularly high when commercial interests are at stake.
There is nothing at all wrong with shortlists that summarize a product's feaures or list its main advantages compared to the competition, or shortlists that briefly summarize a particular topic, or shortlists that briefly summarize an author's personal pet peeves; but there is something wrong with terminological confusion, so don't call such lists FAQs when they aren't. The only proper criterion for a question to appear in a FAQ is: does it come up often in relation to this topic?