In the discourse "Bila Hamaves Lanetzach" (printed in Sefer Hamamorim Melukat vol. 2 pg. 277) the Lubavitcher Rebbe presents the following question: Before the sin of the Tree of Knowledge man was supposed to live for ever. It was only as a result of the sin that death was introduced to the world. If so why did G-d banish Adam from the Garden of Eden, "Lest he stretches out his hand and takes also from the Tree of Life and eat and live forever." Being that the original intention was eternal life, why was G-d worried that man would restore that?
He explains that before the sin, evil and good were two completely seperate concepts. The sin of eating from the tree of Knowlege caused the two to become mixed together, such that no good exists without bad, and no bad exists without good. Now if man would live forever, the bad within him would too. It was necessary for there to be death in the world to ensure that evil would not exist forever.
To answer your question: The Tree of Life was not bad. Rather, after the sin of the Tree of Knowledge it would have been a bad thing for man to eat from it.