I understand the preference for always having a posted user name, so as to follow forum discussions easily and to direct replies to a specific poster, but currently the technology is not in place for securing a guest user name; how then can it be rude not to use one?

There are valid reasons for preferring to remain anonymous; accusations of rudeness or cowardice should not be generalized. If the decision is made to require membership or registration of all who wish to post, there is technology available to facilitate that.