The Muslims want to impose their religion in the government. They do not want religious tolerance. To that end, anyone who is a minority when the Muslims have power is at risk of discrimination. The same is true in Pakistan, especially when the Muslims have a very large majority over the Hindus.
In any city, town or country, when there is a small minority that go against what is normally done in the area, there is a risk of discrimination. Hindus are at rick in Muslim-majority Pakistan simply because some of their practices and beliefs are quite foreign to the majority Muslim population. It does not mean discrimination will occur, but with varying beliefs, it is a risk.
Go anywhere two different religions meet and you will find discrimination. It is basis for people to judge each other. I believe it begins in the school yard. If someone is different, and different religion counts, it is a reason to ignore, taunt, and even beat-up someone. All gods war with each other and their followers gleefully join in.
Pakistan's Islamic laws discriminate against Hindus and other minorities. Hindu people have been treated as separate and unequal citizens. Hindu temples have been desecrated. Hindus have been extorted for money to protect their families from harm. Arrested on false charges, molestation, abduction, kidnapping...all commonplace in Pakistan for Hindu people. They have been discriminated against for many years.