Excellent writers (James Tiptree Jr. among them) have said that they see the action of the story as they write it, exactly like a film, so their use of the present tense is a kind of imaginary eyewitness reporting.
Die große Ursula K. Le Guin über James Tiptree Jr. in Steering The Craft. Tiptree war das Pseudonym, unter dem Alice Sheldon schrieb, die andere große Autorin der Fantastik.