Was Sitchin's work considered to be in the realm of science fiction?
Definitely
Never
At times, but not always
No, it was more often classified as pseudoscience
Answer
Zecharia Sitchin's work is not considered to be in the realm of science fiction. His books, which purport to be about ancient history, are instead more often classified as pseudoscience. This is because they lack any scientific basis and instead rely on wild speculation and conjecture.
The Mythical World of Zecharia Sitchin: Exploring Ancient Astronauts through English Quiz