One of the biggest threats to the act of editing on a project like this is the apathy that comes from user fatigue. By this, of course, I am referring to those users you've seen in your area with a profile and possibly an edit or two that disappears soon after. I'm pretty sure many of the mappers here have encountered this in their work over every area of the OSM database. I've certainly seen it in my short time here. Users that joined, but never made an edit to users that made single efforts and left just as quickly.
Don't get me wrong here - any edits are welcomed and anytime someone adds information to an area, even if it's not perfect, it is a benefit to the project. However, there is something that I noticed about these edits that probably drives part of the reason that these users "give up" after a short time - and that is the fact that most of them start off with something too big and exciting.
Let me explain a bit here - what I mean by big and exciting is the selection and completion of a local feature that is very visible, very famous, and very "noticeable" when it is completed. This is psychologically satisfying because the individual has "added something important" to the database. And they have, make no mistake. And for the people that join just to add that one thing with a singular purpose, their job is done. But to the other enthusiasts, after getting in that super important thing, they are faced with the spectre of what the real job with the maps entails. Thousands of adjustments, correction, additional, alterations and improvements that change the map from a pretty picture into an accurate geographical representation of reality.
It is an unfortunate fact of reality - not all editing is glamorous. It is to those that can stick to that sort of work and plod their way through it that the map has made it to the state that it has reached now and what it will become in the future. As I said, it is just an observation, but it is an interesting one.