An interesting suggestion was put forward by David Golan in his essay "Hadrian's Decision to supplant "Jerusalem" by "Aelia Capitolina"". According to him, Hadrian was part of an imperial movement that wished to return the greatness of the Roman culture, legal system and religion to the shining status it held in the days of yore. This movement came about because of the danger the blossoming Christian movement posed to all of these things throughout the Roman Empire. Hadrian concluded that the best way to quell the Christian movement was by a kick to the face: Building a Roman colony - Aelia Capitolina - in the city chosen by the Christian savior (Jesus) to deliver his heavenly message and erecting a temple for Jupiter Capitolinos to symbolize the strength of the Roman Empire and the superiority of its religion.
In the addendum, Golan discusses whether Hadrian realized that what he was doing would likely incite the Jews to revolt and concludes that Hadrian was probably aware of this, having lived through the Kitos War a couple of decades prior. Nevertheless, he was willing to risk another revolt, not minding delivering another cruel blow to the Jewish People.