I think it would be a bad idea for HubPages to require real name over a screen name or pseudonym. Further, I would conjecture that there are folks who would be forced to stop writing if they were required to use their full names.
For example, consider writers who work for large companies, or writers who are in the military. Their employers are likely to require that whatever they write not be associated with who they work for. Forcing those writers to use their real name would allow those who disagree with them to put two and two together, claim that they are representing for their organization, and fabricate an appearance of misconduct. The result would be that they have to stop, and we as a community would lose their somewhat unique and valuable perspective on whatever question is being considered. In my opinion, this defeats the greatest emerging advantages of the internet, the ability to quickly share diverse perspectives on issues in a manner of civil dialog and civil exchange. This is consistent with what some of us in the U.S. regard as guaranteed by our Forefathers under our Constitution.
Those who resort to name-calling and finger-pointing in this media create their own legacy, no matter what screen-name they use. Further, with respect to accountability, I believe the worst members of the community are dealt with appropriately by the HubPages staff.