The problem with your question is, this is trying to judge US treatment of Pakistan with an Indian glass.
Being an Indian, I have always wondered why Pakistan is so important to US that it would ignore everything it does and still help it.
This thought of you is being raised because you think India is an ally of the USA. But, let us not forget that India's bonhomie with the USA is very much new.
Pakistan protected Osama bin Laden near there army territories.
Not proven by all means. Besides, if that was so obvious, why didn't the USA take any action on Pakistan then?
There agency ISI is protecting many a people having red corner notice and who are wanted by the US ...
This accusation on Pakistan regarding protection of anti-US personnel is relatively new for some reason.
... (like Daud Ebrahim and Hafiz Saeed)
Those two guys are not US's concerns. They are Indian concerns.
They use the money and weapons given for use against terrorists to attack India and Afghanistan.
They provide special railways for events organized by Hafiz Saeed.
There state govts provide funds to the terrorist organization.
But ignoring all this, US always gives it more money and freebie weapons. What is the reason behind this? Also, the people of US don't seem to be speaking against this at all.
Indian narrative, not US.
I guess this is related to the cold war era. Pakistan supported and protected the fighters-cum-terrorists trained by US to fight Russia (USSR). Now those people are troubling Pakistan. So Pakistan expects US to help them. It is kind of, "Your dog bit my son, now you pay the hospital bills".
You have to remember that Pakistan is a nuclear power and a regional player with a very powerful military. As an example: why do you think Turkey can exert so much pressure on the USA and do whatever they like to do around their country?
- They occupied Cyprus.
- They are running military operations in Syria.
- Being a NATO member they are purchasing sensitive Russian weapon system.
- They arrested US officials working in the US embassy in Ankara.
- They once stopped giving away Turkish visas to US citizens.
Pakistan's alliance with China is a major headache for the USA. It is not because of Pakistan, but because of China's growing influence on the region.
The region where Pakistan is situated in a junction of Middle East, Middle Asia, and South Asia. In the past, Soviet Union took control of Afghanistan and wreaked havoc on the US interest. This area has become important once again because of having the potential of hosting Chinese and/or Russian military bases.
Pakistan has a very strong influence on the House of Saud.
Let us not forget that the USA betrayed Pakistan during 1965's Indo-Pak war by stopping civil and military aid. The aid was dropped almost overnight. Even though India had no alliance with the USA and Pakistan had several alliances with the USA and Pakistan was considered an active member of US bloc.
War on terror was not Pakistan's war. But, USA goaded Pakistan into this war which costed Pakistan billions of dollars and lives - both military and civil.