I asked you a couple of post back this question.BhagatSingh ji, Why would Guru Gobind Singh Sahib ji give the order to the Sikhs to keep their hair and why did the Gurus keep their hair uncut?
I don't know I am not Guru Gobind Singh. (been bashed on this forum for formulating a hypothesis of what Guru GObind singh would have thought when doing a certain action. SO I won't be getting into that again)
No proof of whether the other Gurus kept their hair uncut.
Reference:: Sikh Philosophy Network http://www.sikhphilosophy.net/sikh-youth/22759-hair-and-general-sikh-philosophy-study.html

Now since you do not know the answer and you accept the Sri Guru Granth Sahib ji as your Guru, which also means you accept Sri Guru Gobind Singh Sahib ji, then why do you say the Guru did not say we should or shouldn't keep our hair????? Because clearly Sri Guru Gobind Singh Sahib ji said every Sikh must keep their hair.