Why aren't cigars addictive?

It's the pH of the smoke.

Nicotine is addictive if it enters your body in an acidic carrier. Cigarette smoke is acidic, so its nicotine is addictive. (The acidity also prevents the nicotine from being absorbed through the walls of your mouth, so you need to inhale cigarette smoke to get the effect.) Cigar smoke is alkaline, so it can enter your body through the walls in your mouth and it's not addictive.

There's also the part about cigars being so expensive you can't afford to get addicted to them, but that's a side issue.

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I may be wrong here, but as far as I know, you aren't supposed to inhale cigars like you are with cigarettes. And then you won't inhale the nicotine either.