Skeptics Say:
"Reincarnation is wishful thinking on the part of those who don't like to face the prospect of death."
(David Wallechinsky & Irving Wallace)
http://www.trivia-library.com/a/afterlife-and-reincarnation-part-5-critics-of-reincarnation.htm
Criticism:
With reincarnation being a supernatural entity, meaning unexplainable by natural law or phenomena, proof of it by any of the human senses would be nearly impossible. At the same time that does not form an absolute to rule out its existence. Though it is an element of the supernatural, we can't go without saying that it is also an element of religious belief. One of the primary criticisms of reincarnation is that it does not appeal and or adhere to the principles of certain religions. This being, just because some believe and others don't does not mean that it exists or that it does not.
For those who have beliefs in reincarnation, often take into account the element of "Karma". Many skeptics believe that reincarnation and karma are easy ideals to accept, in that they take responsibility for the events of life. This being, many people's belief in reincarnation is fueled by a lack of evidence and a desire to escape the consequential reality of their actions.
Religion aside, more criticisms of reincarnation exist. For example "The Population Problem", pokes at the claim of souls being immortal simply leaving one body at death and entering a new at birth. If souls move from one object to the next, how do we account for the new souls that inhabit the bodies of new objects. Similar to the law of conservation, "matter is not created nor destroyed", the soul is not destroyed, so then how are these new souls being created?
http://triangulations.wordpress.com/2010/08/23/reincarnation-problem-1/
Though this is just one of many criticisms of the existence or belief in reincarnation it makes a valid and logical point, but in the end reincarnation is of the supernatural, something we can't explain. So until someone personally experiments to prove reincarnation, by going through the process of death and rebirth, then there will be no absolute for whether it exists or not. In the end it's a "Catch 22" because who wants to die to prove a point.
(Jamal Daniels)