@notapilot15:
Because people living in a more remote region would also like to be able to go anywhere and will thus like have to transfer through a hub, as for most destinations there is simply not enough traffic for a direct flight with sufficient frequency.
For hubs the simple fact is that twice the hourly capacity means four times the number of possible connections you can offer. Using one large aircraft on a route instead of two smaller ones, means that the saved slot can be used for a flight somewhere else.