I agree that they probably shouldn't cast shadows and I think any explanations there have been to explain that they aren't actually made of light were only invented to make up for the "error" which was caused by the limitations of filming in the late 70's.

The glowsticks comparison doesn't really cut it as these are physical objects that happen to have light produced inside of them. The lightsaber blade is not really a physical object but rather a beam of energy. Last I heard, a laser doesn't cast a shadow and that's what a lightsaber was originally called - a "laser sword"

Whether it's practical to remove them, I don't know. Adywan is ridiculously extensive in his fixing of errors, but as far as I remember, he didn't remove the shadows.