Then why do Watchtower and JW believers often (or even mostly?) use the name Jesus when discussing his enthronement, or who supposedly kicked out Satan from the heavens, or who is gonna whoop the infidels' asses in Armageddon?
Because Michael as the heavenly name of Jesus was never meant to be used in worship, prayer, preaching or teaching. In 2 Thess. 1:7,8 Paul himself uses the name Jesus while telling about the time when he comes for destroying the wicked. For believers, the role of Michael as a heavenly warrior who brings destruction is still to be seen in the future, whereas his role as Jesus the Christ and the redeemer has already been displayed during his time on earth. So Jesus is the more preferred name for believers as Jesus as the Christ has impacted them the most than his role as Michael the Archangel.