If Julius Caesar is to be considered a bad leader, it is likely because he was unable to foresee the political and historical implications of his dictatorship and the entailing manner in which he portrayed himself. Such a conceptual shortfall ultimately cost him not only his power, but his life.
Even before Caesar became sole ruler of Rome, he was no stranger to taking dangerous political risks. In 51 B.C., Caesar defied senate authority and longstanding military tradition when he crossed the Rubicon River to take on his political opponent Pompey Magnus. Such a move signaled a treasonous invasion of his own country. Caesar's ability to inflame opinions did not end there, as with his courting the Egyptian queen Cleopatra, a scandal that nearly ruined much new-found support gained after his ultimate defeat of Pompey at Pharsalus, the battle that effectively ended the civil war.
In 45 B.C., Caesar stood virtually unchallenged by any major political threat, and he used that opportunity to force the senate into declaring him dictator for life, a power it didn't actually legally possess. In subsequent appearances, Caesar took to wearing purple, a color the Romans associated both culturally and historically with the vilified Etruscan kings, the very personages the vaunted Roman republic was originally designed to usurp. In so doing, Caesar cast himself as a tyrant that well-meaning Romans were honor-bound to replace. It is thus no surprise that one of Caesar's many assassins, his one-time friend Marcus Brutus, was a descendant of one of the celebrated families most famously involved in the overthrow of the last Etruscan king.