Why do some journals have anonymous editors?
However why should editors remain behind a veil of anonymity?


My educated guess is that these are the same reasons why peer-reviewers are anonymous:

An editor has to make potentially unpopular decisions, beginning with deciding about desk rejection over selecting the reviewers to making the final decision.
In fact, the editor usually has more power than a single reviewer.
These decisions should be made without fear of repercussions and similar, and editors do not want to pestered about negative decisions outside the journal’s channels.

By the way, all journals that I know to follow such a policy (which are almost all I know) also stop anonymising the editor in case of a positive decision, i.e., the acceptance is usually sent in the editor’s name and thus tells you who handled your paper.