The first dīkśa, initiation is Śiva Sūtra. The first pūjā, sacred ritual is Guru Pūjā, the first Stotra (devotional hymn) is Guru Gītā.
With overflowing gratitude, you pour yourself at the feet of the Master, and in the same way you touch the Guru's feet also. In the ecstasy, you always feel like offering yourself at His feet. There is no logical reason why Guru Pūjā is done, why people touch Guru's feet. It is an emotional feeling connection. For some people, it looks like why should I do it? For some people, it is Life, they cannot live without it. I know, for millions of my disciples, morning satsang is much more important than eating food. This is bliss dose. Morning sitting in the Pāda Pūjā and the morning satsang is the powerful bliss dose. Life is life itself.
So, please understand, it is the individual's emotion. One more thing, do Guru Pūja only if you feel intensely connected to it, not otherwise. It should not be done as a ritual. As far as yoga is concerned, whether you want it or not, it has to be done because you are working on body. But when it comes to Guru Pūjā, it is in your mind, your heart. Your mind, your heart itself should feel it. Out of ecstasy and joy, you should be pouring it. There is no logical reason. What is the reason we do Pūjas at Guru's feet—Gurupāda? Why do people want to touch Guru's feet? There is no logical reason. Just, that is the way it is. That's all. That is the way it is.