Adopting a pseudonym for a thread is a reasonable, if minimal, act of courtesy towards other people engaged in the conversation.

Of course it makes for a somewhat one dimensional presence here, but fair enough, if that's what someone prefers. In any case, no one is ever going to know it's only a temporary pseudonym.

What gets up my nose is when a series of nameless GUEST posts punctuate a discussion, and there's no way of telling whether one post is a continuation of a line of argmuent from a previous post, or a heckle from a new bod jumping in. And that needn't matter, because I generally skip over them - but then other people start replying to them, so that the nameless ones manage to impose their presence on a thread in any case.

I can quite understand when people prefer to post as GUESTs-with-some-kind-of-identifying-name, however temporary. But I cannot see any motive for posting without that minimal courtesy, other than a desire to screw things up. So inevitably, that is how I interpret the practice.