Wikipedia:Not in my encyclopedia

Not in my encyclopedia is a sentiment that expresses the holder's good faith belief that a particular topic, type of article, viewpoint, or content does not belong in Wikipedia. One common variant of this is That belongs in Wikia, the belief that since Wikia does or could cover a topic, Wikipedia shouldn't. This motivation can be due to an editor's personal religious or moral convictions, belief that Wikipedia's reputation is harmed by covering the undesirable content, or other sincerely held beliefs. This becomes problematic when the user attempts to use Wikipedia's content processes to enforce his or her views on the rest of Wikipedia.

Various attempts to influence Wikipedia to exclude the undesired content are responsible for many of the proposed changes to WP:CSD and other deletion processes, WP:NOT, WP:OUTCOMES, and various notability guidelines. While good-faith proposals to remove content or change inclusion guidelines are not inappropriate, the fervency of belief in the rightness of "the cause" may prompt NIME'ers to react hostilely to those who disagree with their belief.

Ultimately, Wikipedia has succeeded to date (2011) in large part because people wrote about whatever they cared about, with a generally level notability playing field and a fairly limited set of exclusionary criteria. Whenever any editor seems to be taking the policy-based inclusion of something against their wishes too seriously, that's a good time to focus on the pillars, and remind them that Wikipedia is not made in their image, but in the collective image of the tens of thousands of users who have built it, and that they are not responsible for re-making Wikipedia in their own preferred image.

Alternative viewpoint
Historically, some have said that Wikipedia aspires to be a serious, reputable reference work. Such works generally have content standards, and some material may be excluded even though it would normally meet inclusion criteria. Wikipedia's standards of inclusion are intentionally looser than those of any comparable reference work, but there's still some material that isn't congruent with our goals, and thus doesn't belong in our encyclopedia.