It's a choice of a posted to edit the prompt or whatever he chooses to edit. He does me (and you and all the people around) a favour by posting his logs here so we could spend some time reading them. If you don't like something about a log - just don't read any more logs of this poster. Bitching about logs is just immature and stupid just as bitching about person who does you a favour.
I do like logs with prompts too but if you look through Istendil or Zorszaul logs - they are prompless too. And no one bitched about this fact back in the days, if we speak about Ahtieli's logs. A character of that caliber has to not reveal everything about itself, you should understand it.