Excellent post, but the points still boil down to logic versus a leap of faith, and even if that leap seems fairly small, it makes all the difference. So let's look at why "life after death" isn't possible, and consequently why nobody is talking to dead people:
The Impossibility Of The Transcendent Self
Virtually all notions of "life after death" hinge on some version of a transcendent "self", generically referred to as a "spirit" that continues to do something we identify with "live" when the material body associated with it dies. Straight off, if this is the situation is true, the initial premise that nobody is talking to dead people remains intact, because if contact with such spirits is taking place, it is not contact with dead people, but contact with living people, minus their physical bodies. At this point the believers are likely to say that this perspective is just a matter of semantics, and that their essential point remains justified. But is it? On closer inspection the answer is, "No", at least not logically. It is still based on a leap of faith that sets scientific evidence and logic aside.
One way of explaining this is to pose this question: Why should we assume that contact with people minus their physical bodies can take place? Let me emphasize here that I say "can take place" as opposed to "is taking place". I say this because I do accept that there have been phenomena that have led people to associate deceased people with phenomena they have experienced. As a consequence that phenomena has then been accepted as evidence that what was being experienced was in fact the presence of a dead person. Logically however, this is not necessarily the case. It may be the case that some third party other than the deceased person is responsible for the phenomena that was being experienced, and for the sake of argument, we can take it for granted there have been many instances involving hoaxes where this has proven to be the case.
So moving along, we have now established that the phenomena alone does not logically prove the hypothesis of life after death. So then what can ( if anything )? At this point it should already be clear that for us nothing can prove life after death other than to experience life after death ourselves. But is that even possible? Again the answer is, "No", because in order to do so, the part of ourselves that does the experiencing of life after death would need to be the same part that does the experiencing of life before death, and logically that simply cannot be the case because all substantial scientific evidence indicates that the part of us that does the experiencing ( our consciousness ) is the product of a normally functioning brain, which is a material part of our bodies.
We've been discussing this at some length over in the Consciousness thread, and it's important to note here without referencing the hundreds of pages, that the evidence doesn't indicate that the brain material is itself conscious, but that it gives rise to consciousness by virtue of its natural form and function similar to the way a light bulb gives rise to light. Just like the light emitted from a light bulb is not a material component of the bulb, consciousness is not a material component of the brain, yet just like light from a light bulb is dependent upon the bulb in order to exist, all substantial and verifiable medical evidence indicates that when the brain dies, consciousness also ceases to exist, and therefore there is little reason to assume that it is maintained by some other mechanism beyond the death of the brain.
However for the sake of argument, let's suppose that there is some other mechanism that is able to revive our consciousness following the death of our brain. Is that enough to qualify as "life after death"? Again the answer is "No". At best, what has really happened is that instead of our original brain giving rise to our original selves, a surrogate brain has taken over and replicated our original consciousness, and we are therefore no longer our original selves, but a copy, and even worse, we have no bodies, which like it or not play a key role in our identity as well as our personalities.
Scientific study has conclusively shown that manipulation of the brain and body chemistry has drastic consequences for our personalities, which apart from our physical characteristics, are all we have left of our "selves". So if we lost not only our bodies, but our personalities, there would be no case at all for any "life after death" in the sense that the people we are and are known to be by our personalities would continue to exist. Therefore in addition to some sort of brain replicating our consciousness, some sort of system that mimics the biochemistry affecting our personality would also have to be involved.
So again, even if the phenomena experienced is real, and apparently seems in every way like the original living person, logically they simply cannot be that person, and therefore, if the stimulus for the phenomena is objective and external, logically the only viable alternative is that some third party is stepping into the picture with a clever copy and making the experiencer believe that the phenomena is actually the original person. There is in my reflection on this matter no reason to assume that anything else can be case. But if you have some way around it, by all means let's explore it. The only other alternative is wilful ignorance combined with blind faith, and we know how that tends to work out.