Media in Pakistan tend to be very anti-American. They are not always doing this out of conviction, but to stay in business. Over the last two decades, Pakistan has relaxed restrictions on starting media outlets. First, it was print in the 1990s, and then electronic media in the last eight years. Now there are thousands of print publications, and nearly a hundred TV stations. What was also expanded was government censorship. Media cannot criticize the high courts or the military. Most other politicians are fair game, but you have to be careful, since the parliament passes laws that regulate the media.
Because there are so many media outlets, there is fierce competition for readers and viewers. Ad revenue and bribes from politicians are often insufficient to cover expense. Many media outlets are often only a few hot headlines away from insolvency. The best source of lucrative headlines is any anti-American story. The U.S. is accepted in Pakistan, and throughout most of Asia, as the designated source of all that is wrong locally. Logic or history has nothing to do with this, it's just generally accepted that you can slam America and never get slammed back.
The American State Department does try to officially reply to, and discredit, all these lies. But there are never enough personnel (or enough media relations people who are really good at it) to get the job done. So America's reputation remains in tatters, and many Pakistani media outlets stay in business.