Before disposables and when i worked in a vape shop, many customers seemed incapable of remembering to change/ learn how to change a coil, always filling tanks via the chimney, using incorrect chargers, not even bothering to charge devices, always smashing tanks and glasses, using the wrong ratio of vg/pg juice, setting the wattage wrong, not knowing how to turn a device on or off, asking for a coil for their vape but not having the device or tank with them - or knowing the name of it - or even knowing where it was. All day long, everyday, it was perverted. One customer came in almost everyday for about a year, his vape wasn't working. Sort him out a new set up and he was back the next day and the days after, his vape wasn't working
Disposables solve all those problems for people, a bit like people who wont make sandwiches to take to work, they buy the bloody things, despite the added expense.