If psychics speak with the dead [i.e. sylvia brown], why don't they ask the questions that really matter?!!

I mean, supposedly she and other psychics talk to the dead right? They tell them things such as messages for family members, how they're doing in the after life, and so on and so forth...but why don't the psychics ask things like: "What is it like to die?", "Where are you?", "Is there a god?", What does it feel like to be a spirit?" I mean, aren't these the things that most of us would really like to know from the dead?!