The reason is very simple.
They do not have the right sized planes. If they would love to be the Business (wo)man's airline, their optimum fleet size would be a 90-105 seat jet. Of course no shrink or stretch, but a baseline model that would allow CASM in region of what a 737-800 with 180 pax offers. That is the level they have to come to.
Now, with no money to finance a complete fleet roll-over now, you have to do that over time. That means, longer time operating larger planes than desired. That also means that you have to fill these planes.
And, one more thing is yet still to be answered.
How to deal with the over-staffing and what to do with
SGS,
STS and Co? A leaner and slimmer
SAS that could contract out their MX and handling to actors outside the
SAS Group would be able to operate with much lower CSAM than todays
SAS.