A) It's expensive
B) It hasn't really been tested extensively and there is the *possibility* that it may be more harmful than regular old nicotine, though it's unlikely if it's decent juice, and you aren't combusting it or heating it to dangerous levels, but it is an unknown factor.
C) It's a good choice for folks who are having trouble switching to just nicotine and can be used transitionally to help with cigarette detox for folks who desire just nicotine. Doing it that way eliminates tar right off the bat (which itself is an MAOI, so you would be detoxing from that anyway), if using WTA and slowwwllly weaning off of it, lowering percentages in the tank can ease detox and also control the reduction in WTA fairly easily as compared to trying to do that with cigs.
D) I think you are probably unfamiliar with nicotine absorption rates with e-cigs compared to tobacco.... It may be a higher percentage nicotine, but vape absorption is less efficient than cigarette absorption. Also, nicotine isn't just the "strength" you use, it's also how much cumulative e-liquid one uses over the course of a day. A MTL vaper at higher nicotine may be getting LESS nic if they use 3--4 ml a day versus a subohmer who may use up to 30 mg of juice a day (that's high, but not unreasonably high for subohm necessarily) but use only 2 or 3 m.g. liquid. So, you really are saying that people are using "higher" nicotine with perhaps not as much knowledge about it as you think. There are folks on here who can do that calculation quite easily, one of them may chime in. I don't know exact numbers, but the mg/ml in a cig performs quite differently in a cig than a vape. So that's a bit of a red herring, using WTA may satisfy you more, but that's due to all the other things in tobacco, not just the nicotine level itself. Each person is going to have to experiment to find the right nic ratio for them, and that has nothing to do with added WTA. Most WTA juices have nic added on top to reach a consistent nic level, so knowing what your WTA nic level is will be important. It's not as simple as "Oh, it's WTA so my nic level doesn't matter." They both do.
E) Many e-cig users don't want the alkaloids and do fine with plain nicotine juice. There's no reason TO use WTA other than preference. I used it to taper and I keep it around for stressful moments, but I don't always use it regularly at this point. If I save it for high stress situations rather than vaping it routinely, it's another weapon in my arsenal for staying of cigarettes, which doesn't sound really like your motivation.
It makes perfect sense for you to use WTA if you prefer it and can afford it, but since you aren't quitting, and claiming you don't even need nic, I'm unsure why you think everyone should vape WTA. You're not in anyone else's situation, and I don't believe it to be true that "most" vapers use more nic (or at least absorb more nic) than they were smoking, necessarily. In fact, I find that vaping SOELEY allows me to use less nicotine, and vape less than when I was smoking cigarettes. I can go hours without vaping if needed, and I certainly couldn't do that with cigarettes. My "need" to vape is far less pressing than my "need" to smoke cigarettes. Oh, many of us chain vape starting out, that's not unusual while going through the detox process but most ppl's nic usage settles down.
Best of luck with all the variables you will be playing with. Please note that I think it's perfectly fine for you to use WTA if you like it, but a blanket statement that WTA is "best" isn't really exactly true, at least not for everyone.
Anna