The practice of medicine is not actually that hard. It's all about risk profiles and benefit tradeoffs. The Lexapro I have been prescribed for my anxiety and the Advair for my asthma could very well be more dangerous for me than any trans-dermal Nicotine patch might be.
Our Food and Drug Administration has decided that it's relatively safe for me to buy Nicotine in whatever amounts I want without any more restriction than me being more than 18 years old. They've decided that Advair and Lexapro have risk profiles worth forcing me to go through my doctor before allowing me to have any.
We have thousands of years of data that shows Nicotine doesn't just randomly make you want to kill yourself. We have a lot of evidence that smoking tobacco can increase risk of cancer, and that the additives in commercial cigarettes can increase that risk a lot, but that doesn't apply to Nicotine specifically. There is some evidence that any sort of lung irritant can increase the risk of lung cancer, so even vaping might not be completely safe, but neither do we know the magnitude of that risk, especially separate from the many other irritants we're exposed to on a regular basis.
I'm not trying to advocate for using Nicotine. There is a risk of smokers pointing to information like this and saying "see, my disgusting habit is not that bad". That's not at all what I'm saying. But just because I don't have MD after my name doesn't mean I can't make informed decisions on my own about my own treatment. I'm just sick of this infantilizing concept that intelligent adults can't figure out a few things on their own.