You are highly mistaken. Sikhi is the power of bravery. Baba Banda Singh wasn't a Punjabi and how many out of Panj Pyare do you think were Punjabis? Guru Sahib wants a Sikh who can sacrifice not someone who is a Punjabi.
Quite honestly, it is not a matter of what Guru Sahib wants. It is a matter of who are sikhs? Sikhs are 99%+ punjabi. Again, beyond the foo foo of egalatarian and equality bs, Bihar and UP and madrasi sikhs would not behave, think or sacrifice as Punjabi sikhs. That is not prejudice, that is fact.
I am reposting an excerpt below, from another thread to support this line of thought. If you are off in the heights of spiritual meditation and intellectualism, you are very much correct, it does not matter who is who, as we are all born fundamentally equal.
Excerpt from Khuswant Singh's History of the Sikhs, Volume 1, page 15.
"The Jat's spirit of freeom and equality refused to submit to Brahmanical Hinduism and in its turn drew the censure of the privileged Brahmins of the Gangetic plains who prnounced that "no Aryan should stay in the Punjab for even two days" because the Punjabis refused to obey the priests. The upper caste Hindu's denigration of the Jat did not in the least lower the Jat in his own eyes nor elevate the Brahmin or the Kshatriya in the Jat's estimation. On the contrary, he assumed a somewhat condescending attitude towards the Brahmin, whom he considered little better than a soothsayer or a beggar, or the Kshatriya, who disdained earning an honest living and was proud of being a mercenary. The Jat was born the worker and the warrior. He tilled his land with his sword girded round his waist. He fourght more battles for the defeence of his homestead than the Kshatriya, for unlike the martial Kshatriya the Jat seldom feld from his village when the invaders came. And if the Jat was maltreated or if his women were molested by the conqueror on his way to Hindustan, he settled his score by looting the invaders' caravans on their return journey and freeing the women he was taking back. The Punjabi Jat developed an attitude of indifference to worldly possessions and an instinct for gambling with his life against the odds. At the same time he became conscious of his role in the defence of Hindustan. His band of patriotism was at once hostile towards the foreginer and benign, even contemptuous, towards his own countrymen whose fate depended so much on his courage and fortitude."
My point being, at some level, one must acknowledge the people of the land of the five rivers as being integral to the backdrop of modern sikhism.
Majority of the people in Sikhi are Punjabi but it doesn't mean only Punjabis have the right to it. If one follows Sikhi as instructed by Guru Sahib then anyone is capable of becoming a true gursikh and sacrifice. There were non-Punjabis in the Khalistan movement who took amrit and gave up their lives. What we lack today is proper rehat and naam simran. If 99% "Sikhs" are Punjabis then keep in mind that 99% traitors have also been Punjabis. Sikhi, Gurbani and power of Amrit liberated the people of Punjab.
We are talking about different aspects of sikhism. You are not wrong, and neither am I. There is a reason sikhism has not spread beyond punjab, and that is a complex issue, too long and too subjective.