I got this idea from StuffOfInterest (see User:StuffOfInterest/Userboxes), after looking around to figure out why my atheism and moral realism userboxes got changed from endorsements of the two ideas into the milquetoast "this user is interested in...". I think the rationale for NPOV is an absolute must - for encyclopedia articles. NPOV is inappropriate for userpage content though. See User:StuffOfInterest/Userboxes#Userbox_war for the details on the uprising of would-be userpage-NPOV enforcers.

For individuals speaking for themselves to be prevented from expressing points of view, would make Wikipedia worse off. Expression of personal points of view on userpages helps others better appreciate your perspective on your edits; more importantly, it helps Wikipedians get to know one another and fosters a sense of community, rather than faceless anonymity. Besides, no one is fooled by the supposedly NPOV-ized replacement userboxes indicating that "this user is 'interested in' atheism", "this user is 'interested in' Christianity", etc.; we all understand the expressions of personal points of view inherent in those milquetoasted userboxes, though we must do so with the annoying mental step of de-Orwellianizing them. Wikipedia is privately owned and so can offer whatever services or prohibit whatever expression it feels like on its servers. However, expression of personal points of view is inherent anyway in any userpages, messages to other users, or discussion pages. I don't think efforts to prevent Wikipedia servers from being used to convey individuals' personal points of view in userboxes are meaningful unless they also do away with userpages, user talk pages, and article talk pages.

Cross-posted at Wikipedia_talk:Proposed_policy_on_userboxes#Preventing_personal_POV_in_userboxes_is_neither_feasible_nor_conducive_to_community.

For a thoughtful representative counterargument, see User:Proto/Userboxes Are Evil And Must Be Stopped.

Reaverdrop's userboxes:

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Beliefs:
  This user is a materialist, and believes that everything that exists is made of matter.
{{User:Reaverdrop/Userboxes/materialist}} - The classic materialist userbox.
Wikipedia philosophy:
  This user believes that Wikipedia is better off with NPOV inapplicable to userboxes and user categories.
{{User:Reaverdrop/Userboxes/User freedom}} - This is a modification of one of StuffOfInterest's userboxes.
  This user believes that NPOV does not mandate a no-fact zone.
{{User:Reaverdrop/Userboxes/wiki-npov-facts}} - Another statement of Wikipedia philosophy; see for instance my comments at Wikipedia_talk:Neutral_point_of_view/Archive_020#Pseudoscience_subsection_contradicts_rest_of_policy.
Personal interests:
  This user is interested in space exploration.
{{User:Reaverdrop/Userboxes/Space_exploration}} - My custom physics userbox, which is cooler than the standard issue.
 This user is interested in physics.
{{User:Reaverdrop/Userboxes/physics}} - My custom physics userbox, which is cooler than the standard issue.
  This user is a novice clarinettist.
{{User:Reaverdrop/Userboxes/clar-1}} - My remake of user:clar-1, with an image of a clarinet added.
File:Truthiness2.JPG This user wants you to know that you're on notice.
{{User:Reaverdrop/Userboxes/colbert-truthiness}}
{{User:Reaverdrop/Userboxes/colbert}}
  This user subscribes to The Colbert Report on iTunes.
{{User:Reaverdrop/Userboxes/colbert-report}}
  This user plays Protoss on StarCraft and can beat you.
{{User:Reaverdrop/Userboxes/protoss-reaverimage}}
  This user has a deep spiritual connection with the Protoss.
{{User:Reaverdrop/Userboxes/protoss-loyal}}
This user will suddenly vaporize your base by dropping reavers into the middle of it.
{{User:Reaverdrop/Userboxes/protoss-reaverdrop}}