Honestly, much like Cigarettes, Cigars, Cloves and Etc. Vaping is a fad.
It is incredibly expensive fad that to me doesn't promote a social atmosphere (i.e You necessarily don't want to share it with people even if they are your friends or family and half the time people are sneaking it like its a dirty secret imo OR People flash it off like it is a new piece of jewelry and get in your face over it like OH LOOK AT ME I HAS A VAPE NAO I COOL TOO?) and the convenience for some varies depending on their set up or how much they have spent on it. I say this because I have smoked or tried vape on a couple of different set ups and found that the 'drag' or inhalation was like an attempt to suck a golfball out of a tiny tube and the process of refilling the 'flavor' was a colossal pain.
Not saying that it isn't neat and I hope that I could have one that doesn't have the drag consistency of a thick milkshake but to me like mattarios2 said - collecting vapes and their hardware isn't the same to me as collecting hookahs that are hand painted, made of glass or have intricate details.