Why was Tartuffe such a jerk?

Tartuffe's superiority lies in the fact that he can accurately analyze the weaknesses of his victims and then exploit these flaws for his own advantage. He is no simple or ignorant charlatan; instead, he is an alert and adept hypocrite who uses every means to bring about his success.

In some ways, Tartuffe uses Christianity much like some present-day televangelists — as a means to extort money from the naïvely faithful. But Tartuffe's motivation seems to reach beyond greed: He wants dominance, just for its own sake. Some contemporary psychologists suggest that up to 5% of men and 1% of women are sociopaths (meaning they have what's called "Antisocial personality disorder"). Symptoms of this disorder include a complete lack of conscience: a pattern of conning others for personal profit or pleasure and a lack of remorse at having hurt, mistreated, or stolen from these victims.

Sounds like Tartuffe, if you ask me.