Because, after Valerius Gratus, he was the only Roman governor who ruled more time than any other Roman governor of Judea:
Coponius : 3 years.
Marcus Ambibulus: 3 years.
Annius Rufus: 3 years.
Valerius Gratus: 11 years.
Pontius Pilate: 10 years.
Marcellus: 1 year.
Marullus: 4 years.
Cuspius Fadus: 2 years.
Tiberius Julius Alexander: 2 years.
Ventidius Cumanus: 4 years.
Antonius Felix: 7 years.
Porcius Festus: 2 years.
Albinus: 2 years.
Gessius Florus: 2 years.
Why Pilate and not Valerius Gratus? Because Valerius Gratus was for 2 years governor also of Syria. Probably this made the difference between him and Pilate, in the choice of the first euhemerizer.
Why Pilate? Because of the his long rule
Why Pilate? Because of the his long rule
Nihil enim in speciem fallacius est quam prava religio. -Liv. xxxix. 16.