It may be a mild catalyst but it isn't the prime reason. You know it very well. There aren't enough cross border raids to give rise to such an unrest in Pakistan. The present anarchy started well before any Nato attack. The dispossessed Taliban fled from Afghanistan and found refuge in FATA, which is home to their brethren and many of their ilk. As I have already said, the Frankenstein's Monster has turned upon its own creator.
In case you forgot the monster was given weapons and training in 1980s. In 1990s they only got some fuel.