It's a good question and I think your insights into it with regards flavoring are onto something.
I also think that there is a lot to be discussed on this topic from a historical perspective as well. My experience years ago was that ALL juice was PG and from China. Some companies would sell special gimmick products to add extra vapor to your juice like flavorless VG, and there was another one I can't remember that didn't catch on. The Chinese didn't change the way they produced atomizer, clearomizers, and cartomizers to wick properly with thicker juice though and now there is a huge mess with folks getting a burnt taste with heavy juices and they don't know why.
Darkhood, so eloquently stated that we are a first world nation without universal health care, but he failed to mention that we are also the oldest cigarette smoking nation. We exported the habit. Other nations tax smoking higher than we do to pay for the health cost and acted quicker to embrace
vaping. As a result of us acting slower we were able to take advantage of VG being a superior vape than PG.
The correlation between Chinese
vaping devices to incompatible American e liquid is dramatic. For example, try 100% VG in a vivi nova, kanger t3, CE 2,3,4,5, or a cartomizer and you see an obvious disconnect.
If these products actually worked NOBODY would bother with a hybrid mod.