Why, is there a limited supply?
It has been my experience (from eating my sister in law's pie) that the best pies are made with fresh fruits not frozen. As a result of the growing season and wanting fresh fruit, the best quality pumpkin pies are in the fall to maybe Christmas. With such a high demand for such a superior product, the preferred varieties of the fruit can run out. Naturally I had assumed you wife, being a discriminating chef, only used the best varieties.
Ted
My wife, "being a discriminating chef" does not use pumpkin in her baking!
They probably didn't have pumpkin pie growing up in Ireland, I presume.