@umerIdrees - I have the same concern, seems like you are the right person to ask this. Why did NZ team ran away before the start of the series, I read it on internet that Pakistan PM, who himself is a cricketer went to the field himself and assured them that everything is fine even he spoke to NZ PM but they refused to play and went back. I have heard the same rumors in Aussie case, but seem like they are a bit daring to take the stand.
Well NZ team received some suspicious email that they will be attacked if they play the series in Pakistan. They decided to fly back. It was their own decision or it was influenced by BCCI, the details are not public.
It's their stance and will that they opted for what they think was best for them but they didn't know what was coming afterward. Later everyone told them that they did wrong.
Pakistan got more strong with their verdict and we gave a clear statement that if any country wants to play with us, they need to come and play here. Best security will be granted and No neutral grounds will be accepted. If Australians had refused this tour, we would not have gone next year to their country.
Lesson:- Be strong, be a lion and the world will respect you.