i think its the inferiority complex of some people of western IS, the reason is, they always suffered the brunt of british colonial propaganda as being the vanquished ones and pashtuns as conquerers, the punjabis and western indians feel the need to associate themselves with the conquerors rather than the conquered.
if punjabis obthered to read some historic sources, for instance the hou hanshu, you would be surprised how it refers to kabul valley as the conquered place, some times by central asians and some times by the indians. such kabul history and on other hand pashtun people celebrated as the great conquerors.
the reality being the british projection of all turkic invasions as pashtun rather than turkic to go with their aryan philosophy of fair skinned aryans as it was called aryana by the iranians.
regards