Can't I just squish my feather pillow up under my neck?...

You can scrunch up your pillow under your neck for more support. The problem often with a feather pillow is that it won’t hold the needed support. It will flatten and you lose neck support. We want to try to keep are normal neck curve if possible. Hence the creation of the “neck” pillow, or cervical pillow. Some may call it an orthopedic pillow or chiropractic pillow even.