@dsiluvu : In the normal process, A guru will give you the refuge, then Yidam practice, followed by Protector practice. To receive sign from Yidam practices we needs merits, due to degeneration time, people these days want to have quick fixed instead of spending time meditating, doing the preliminary practices.
The Lama is very compassionate as to receive sign or result through Protector practice, the merits required is lesser than Yidam practices, but by giving the protector practices to modern people, when they see some result, they will slowly want to practice Dharma more. What beautiful is that Dorje Shugden is Manjushri, the 4 drakpas, hence relying solely on Dorje Shugden, not only we can solve our daily problem, we can achieve enlightenment through this powerful protector practice.
Wrathful deities are not only found in Vajrayana, but in Mahayana, Hinduism, Taoism as well. So i think should not be a problem to others to accept once they know the benefit of relying a enlighten Dharma protector.