Why should we treat Consciousness separately from Physical Reality?
The reason is that, like Matter and Energy, Consciousness and Physical Reality appear to be different. Whether or not they, like Matter and Energy, are actually the same, remains to be seen.
Consciousness, by definition, is the Observer. Put another way, Consciousness is the Subject and Physical Reality is the Object. The former is always observing the latter -- it is never the other way around. This is why Consciousness must be experienced and can't be measured or tested -- only objects can be measured or tested.
Consciousness does have some unique attributes. It only appears to be present in living beings, although it may be the case that Consciousness is what defines a living being. Either way, there is some amount of physical dynamism that seems to always be present with Consciousness. It may also be that Consciousness doesn't need a physical body for it to exist.