Why we can used PFI for inductive load?

If I understoo your question, you mean why we use PFI for inductive loads. | would answer as follows:

In fact with inductive load part of the power keep oscillating between the load and the supply(grid or generator). This portion of power is call reactive power its function it is only to maintian the excittation for the required magnetic field for the balancing reverse emf. The reactive power doesn't share or convert to the actual work( e.g. the shaft Hp/Kw). Thus, this part of power un-necessarily room in cables, transformmers, generators and switch gears, and that cuases drop in the terminal voltage at the load side. Thus by releifing these apperatus from this un-nessarily burden by the use of capacitors or synchronous motors/condensers at load side we can free up more room in the apperatus and will reduce the voltage drop. And that also increase the stability in the supply grid.