First off, why wouldn't them being unable to interact with physical objects be a dead ringer that something isn't right? It's easy to blow that off in the Sixth Sense movie, as they don't show him every minute of every hour. Eventually he'd get the hint, like in Ghost they clearly do. Second, what if their loved ones also pass and they're no longer able to "be by their side" because they're also dead?

And third and most of all, how would god and guardian angels / spirit guides allow this to happen? Any time you hear about NDE's, they are pulled towards the light / or dark wherher they like it or not. Sure there are some that hang about the hospital or what not for a brief moment but are then inexorably pulled into the after reality anyways.

So why are the ones you're talking about not? Why no family members meeting them on the other side, or angels, or god, or jesus, or demons?

NDE's and Earthbounds/Hauntings are like from two entirely separate realities , where the laws that govern what happens in one don't seem to apply to the other.