I would argue that nicotine is not a controlled substance, so it doesn't fall under this definition anyway.
But, that said, it is totally valid to argue that a definition is wrong, misleading, or incomplete. Has nothing to do with whether I like it or not, but thanks for saying that.
It would be a tautological argument for its addition to the list of controlled substances. Like so, "It's a narcotic because it's a controlled substance and it's a controlled substance because it's a narcotic." Calling it a narcotic is not helpful.
I do wish you would stop taking jabs at me personally.
You don't like the definition. The definition, however, exists.
Regarding the second: We're discussing its regulation here and now.
(Updated to clarify which aspects of comment I'm responding to, and how.)