The Other may have initially taken the name Doctor, but had to forsake it and start again in light of what happened at the dawn of time travel. Since we know next to nothing about the dawn of time travel, this is relatively fertile ground for a writer.
The dawn of time travel is more enticing and more mysterious than the Time War. An origin story also ties in better with the idea of celebrating and commemorating the anniversary of "Doctor Who" than an event that chronologically happens toward the middle (relatively speaking).
Doesn't the fact that SM completely dodged the actual Doctor's name and the fact that every answer he provides in his stories is just provides a set-up for more questions clue people in that he is the last person who is every going to provide a origin story?