It's the new game engine. With a RI of 0 when you first start, you can only attract 10%-20% of the demand. So if you start out flying 80-100 pax routes, you will only get 8 pax to 20 pax per flight initially. It will build up to the full demand as your RI increases.
So you have to (a) start by serving huge routes, or (b) use lower fares to start, since price actually matters now, and gets you more pax, or (c) invest in route marketing, or (d) just save your start-up cash for a while to cover your losses initially, and expect to lose money for a few months, at least until your RI gets up to 30-40 or higher.