First, the way you are pointing is dated of July 2010. It's not really recent.
The question about level of detail is a long-standing debate in OSM. Some people are just interested by motorways for their car navigation system. Some others want to add hospitals and related parking areas for their grandpa. Or map in details funparks, zoos. Others want to say which amenities or shops are accessible for wheelchairs. Mountain bikers or hikers wants want to know the difficulties related to a countryside path. Etc, etc.. So the level of details is all related to the level of interest and motivation from the contributor. Of course, one disadvantage of high details is that it becomes harder to maintain in the future. This is a pending issue. At the moment, we tolerate details if they are not excessive like 20 nodes to describe a small curve. Or attributes that are really not related to the OSM project itself (e.g. price lists). In other cases, we all appreciate that the level of details is increasing in parallel with accuracy with the number of new contributions. What is not acceptable is that someone downgrades the quality of other's contributions just because he doesn't like so much details on his map. Don't forget that the main slippy map displayed on osm.org is mainly for contributors. Other web sites may choose to render less details on their map if they want a more readable map. But that is a rendering and design decision, not something you can decide for others in the database content itself.