I will argue that although upright hybrid posture may seem more comfortable at first, for longer rides dropped bars are the way to go. Another reason is because of reduced surface area, which makes a HUGE difference in a headwind, or when you're trying to go fast on the flats. Another reason is that you can change your hand position all the time, which not only eases the strain on your hands, but also enables you to be more or less upright, which makes it easier on your back. Despite being great bikes, touring bikes are very difficult to find nowadays. Because most first-time bike buyers don't know very much about bikes and what they want to do with them.
Mountain bikes are cool, and people think that dropped bars are only for racers.
So regular folks buy hybrids, and indeed they find that they're very nice for short rides when they want to go at a slowish pace. But if they want to go farther or faster, they soon find that they don't have the right bike. So in most cases they go out and buy racing bikes, and keep the hybrid for short slow trips. This may be OK for someone with alot of space, who can store 2 bikes, and who has enough money to buy two bikes.