Why is it called plantar fasciitis when it is not a fascia which is inflamed, but the plantar aponeurosis?

Let me try to help: Originally, plantar fasciitis was believed to be an inflammatory condition of the plantar fascia. However, within the last decade, studies have observed microscopic anatomical changes indicating that plantar fasciitis is actually due to a non inflammatory structural breakdown of the plantar fascia rather than an inflammatory process.