If the health insurance companies are really trying to help people live healthier, then why are smoking cessation drugs not covered by insurance?

I used Chantix to quit, and it's wonderful stuff, but at $300 a month it had better be! For me it was worth it, but I had the extra grand available for the 3 month program. Many smokers do not. It seems to me that the insurance companies would be far better off paying $1000 now rather than the 10's of thousands later, but hey, that's just me.