The key component that you are missing is the tobacco extracted base. If you recall in one of the posts, Ben did say that it was nearly impossible to make Boba's in zero nic because of the small amount of nicotine already in the base. Also you have to remember that just because something smells good, it doesn't always taste like it smells. Found this out the hard way by licking strippers, don't ask me about it but I am sure a lot of guys here can relate.
You cannot mimic a taste by recreating the way it smells, same reason that all the so called flavorings from PA were a big fail for me. While they might be perfectly fine when used for what they were initially intended to be, a perfume or fragrance, I don't want any of those chemical tasting perfumes in my juice.