I did read, sort of anyway, that entire article. I also looked at almost every related link that was on the page. Most of the article, and the references, may as well have been written in Sanscrit or Ancient Martian from my perspective as a layman. One thing I was able to glean is that at least 80 or 85 percent of the references, again, talk about addiction to nicotine as related to smoking, not as a standalone substance. I again have to mention all the "enhancements" used in modern cigarettes that "improve" the effects of nicotine on humans.
There are many descriptions of how nicotine effects the brain and causes a reward or pleasure sensation. That could certainly make it addictive, but I couldn't determine the strength of the effect due to not fully understanding the verbiage used. I again have to mention that many, many, foods, substances and actions also produce similar, or the same, effects on the human brain and are not considered "addictive" or may be considered mildly "addictive".
In everything I read, and semi-understood, there didn't seem to be any study or reference to nicotine only. Everything seemed to be based on smoking and its' effects on health and including nicotine as the driver for smoking.
I'd love to find something authoritative, reference able, peer reviewed and in language the average layman can easily understand stating that nicotine is addictive and demonstrating how that conclusion was reached.
As a layman with an interest in determining the real level that nicotine may be addictive, I am keeping an open mind. I'm not convinced, totally, either way. It does demonstrate properties that could easily lead to addiction in some people, perhaps genetically related, but so do a whole host of other things.