I think that one has to put some faith in people and not assume that they are all out to grab some unfair advantage and therefore must have their requests rejected out of hand.
Mike, that is nice in theory, but in reality, a very large majority of update requests are self serving. Part of this comes from the fact that people do not understand that a listing consists of three elements: the category name, the title and the description.
Since someone mentioned dentists, let me try and cobble together a quick example:
Category: Regional/someplace/Localities/Anytown/Health/Dentists
Title: Joe Smith, DDS
Description: Provides information for patients, introduces staff, covers insurance options and services offered.
Now, if someone comes along and wants to add the name of the community or the word dentist to the description, it is going to be declined because both are included in the category. Similarly, we are not going to repeat the dentist's name in the description because it is part of the title. If someone wants to add promotional language such as "Ask about our discount on X-rays" or "friendliest dentists in town" or the "half off on second cavities" special, those are also going to go by the wayside. Those are also what we broadly refer to as keyword stuffing.
Are we going to give an excruciatingly long list of the services offered, probably not. Might we pick out one or two that seem unique -- possibly, but telling surfers that they can find a list of services is sufficient. Similarly, we are not going to play alphabet soup with accreditations. We have no need to list them.
We are building a directory, we are not a listing service and frankly, few editors are going to waste their time tweaking descriptions that are already compliant, just to satisfy the marketing or ego needs of the site owner. When someone suggests a cosmetic change to an ODP compliant title and description, the request is rarely going to be honored.
Present information that a listing is factually incorrect (we say there is a map and there is no map) then we will give it all the consideration it deserves.
A quick aside: I was an editor/reporter for a major metropolitan daily newspaper (one of the top 20 in terms of daily circulation). One of the senior editors (who dealt with the most junior reporters) had a sign on his desk:
Life's greatest orgasm is neither sex, nor power, nor money, but the ability to edit other people's copy.
We see a lot of that here -- webmasters, marketroids, and SEO types who want us to waste our time making unnecessary (for us) changes to titles and descriptions in the hope of gaining additional competitive advantage.
I really would like to know. 