Wikipedia - Excluding knowlege on "principle" = Bad

Wikiscanner has been getting a ton of attention lately. With articles cropping up all over the place detailing editing "abuses" by corporations, the government and PR firms.  When you look over these articles or, perish the thought, actually use wikiscanner yourself, you end up finding that abuse is fairly rare.  Most cases of changing articles are factual in nature.

However, there seems to be a very vocal group of folks who think that any change in wikipedia information by a corporations/government agency or a public relations firm is taboo.

I think this is crazy! 

Wikipedia is about creating the most expansive base of factual knowledge possible.  The plain fact is that, often times the people with the most depth of knowledge on a topic are people who work at - or work for - the entity that the facts describe.

If you want to exclude information about the CIA just because it comes from a CIA employee you will possibly exclude the most accurate and timely information.  The same is true about a General Motors product being described by a GM employee, or a James Blunt entry being edited by James Blunt's PR agency.

I have no problem with full disclosure.  Editors should let folks know their background in their profile.  And this is especially true if they have a connection to the topics they are editing. And people should not be entering opinion, or "edited backstory" about their corporation/agency/clients.  But facts should not be excluded from them based on thier emplyer.  In reality, facts should be demanded of them.

To decry editing from classes of people that may have usful information to add should be considered antithetical to wikipedia's mission. To claim otherwise is to lock up knowlege based purely on ad hominem grounds.  And that's a ridiculous waste.