aah and there is no difference in bowing head in front of guru granth sahib or idol worship.both same.
if u dont bow in front of idols then it doesnt mean that u get right to bow in front of guru granth sahib.
why do people bow infront of idols?
because to show respect.
whats the big difference.
Muslims bow to the Kaaba. Why? Because Islam teaches that Muslims must submit and bow to Allah. And since there is no physical direction in the world in which Allah exists according to Islam, Muslims do sujood in the direction of the Kaaba, the house of God created by Ibrahim, built as a mirror image of Allah's abode in Heaven.
You could say that Sikhs bow to Guru Granth Sahib for similar reasons. Just as to the Muslims the Kaaba is the reflection of Allah's glory, to Sikhs Guruji shines with the reflected light of Waheguru's glory. Waheguru is like the sun, Guruji is like the moon. By bowing our necks to our Guru, we are in fact bowing to Waheguru.
I apologise for any mistakes in this comparison if I have made them, and if that is the case could someone more knowledgeable correct me.