Why hindus criticise sikhism

I was listening to Giani Maskin ji katha -"HINDU ANDHA".This is true that whichever person is in the front people will criticise him,whoever is behind will never be criticised.Since,hindus have been criticising sikhism since the first GURU NANAK DEV JI.Our Guruji gave logic for everything hindu said against them and even the rituals and caste system was not accepted by GURU JI.I am not against my Hindu brothers who understand sikhism and love sikh religion but the religious hindu leaders are shouting that sikhism is form of hinduism.I really dont understand why these people instead of practicing their religion are more concerned about things which they are unable to understand.Only if a hindu practice his religion will understand there is no need to argue over this point but to practice your religion.As our great Saint Soldier Sant Jarnail Singh bhindranwale said"Hindu pura hindu bna"Sikh puran Sikh".HINDU Andha kyon hai-I can explain you in the next post.