In the next few years, JUUL and other pod or AIO users will probably outnumber us--the hobbyist/tinkerer vapers.
The reason is simplicity. You charge it, you attach the pod, you vape it and you throw it away when it's used up.
I know they're refillable, but that aspect only appeals to tinkerers like us.
In the age of microwave popcorn, instant mashed potatoes, Starbucks coffee and internet everywhere on demand, this is what today's smokers want. If it's not (almost) as easy as buying a pack of smokes and lighting up in seconds, we're the only ones interested.