Guru yoga is indispensable in any vajrayana teaching. The whole path can be summarized into guruyoga.
I think you should share what you consider guruyoga to be and maybe Steve will be able to correct the assumptions.
In anycase, guruyoga is not about personality cult. You do not pray to your teacher's body or personality. That is why we should not pray to our physical form teachers until we see them the same as the Buddha, Guru Rinpoche, Milarepa or other fully enlightened being. Until you see them like that you use visualizstion of Guru Rinpoche, Vajradhara, etc. and unify all your teachers in their form as it represents and is the same as their enlightened mind.
And through offering,praying and praising you purify yourself, develop merit, develop devotion snd on basis of that will realize budhahood in this life or through the hook of compassion go to the purelands or at the very least be born in higher realms.
Guruyoga is for purification, guruyoga is for blessings, guruyoga dissolves hindrances and obstacles, guruyoga is the best phowa, guruyoga leads to pure lands.
It ofc has to be connected with and grounded in the basics like renunciation and bodhicitta. Without these, you are lost.
Sorry for my ramble heh.