Reason 1: He had good intentions but did not do the right thing and tried to fix a problem that was not broken. Evidence: In the beginning of the movie Jack is not content with being just the pumpkin king and felt the need to find something more and tried to be something he was not by kidnapping the real Santa Claus and deliver presents himself. Despite his intentions; the toys he created backfired and terrorized the children.
Reason 2: He did not