Perhaps the goal is to make the community comfortable for people coming from a culture where real names are the norm.

There are lots of people like that, and most are not going to change.

For quora and facebook, communities with a "real-name culture", a sufficient percentage of real-looking names is sufficient.

People on sites like DW and LJ need to realize that they are advanced, experienced users, but most of the internet users in the world are not.