I think because it's "horses for courses". I use a little on long journeys (50+ miles) but I find there's no need on my commute (20 miles each way). However everyone's physiology is different so not everyone will find it benefits them in the same way, or even at all.
But yes, if it works for you then carry on using it... Also means your wife will never have to struggle to find something to buy you got Christmas!