On the contrary, it was a plan to further the progression of all the spirit children of the Father and allow them to gain a greater knowledge and obtain a body with which they could be resurrected with which brings greater joy and happiness in the eternities.
Giving the children of God the opportunity to progress and receive an immortal body is not personal aggrandizement. Especially when He had to suffer for the sins all mankind to bring about the immortality of all mankind and to give them the opportunity to repent and receive mercy for their sins.
The reason God blocked Adam and Eve from the tree of life was to allow them a period of time to experience the world of good and evil and repent of any sins before receiving immortality. Receiving immortality before gaining the chance to repent would ensure they would not have a chance for eternal life. Giving them a probationary period to repent would allow them the opportunity to repent which could lead to eternal life on top of immortality. For this reason they were blocked from the tree of life until they had the opportunity to repent and gain further knowledge of good and evil.
I do agree that the events of the Garden of Eden were a success and that we have been given a great gift to be able to have knowledge like God of good and evil in this great school of mortality.
I think your lack of understanding the works of God has led you to judge the Almighty according to your lack of information.