Do you know Why Employees Hate HR ?

Because they think HR is there to protect the interests of the employer.

Most employees think that HR is only responsible for hiring and firing... I can see that it would be the reason to "hate" HR, besides docking money from their paychecks for being late or even not coming in to work. Written warnings when they think they can get away with things all the time.

Because of their attitude. HR should answer in polite manners whatever the question of the employee and shall give their honest answer. In my previous company, I never had an issue with our HR because they are informative and polite.