I don't get it. There is roughly a 33%/33%/33% load factor there. My ERJs are 55% Full. That's not much, but, it means their Airbuses cannot be more than 30% Full.
If they were 50% Full, of course they'd earn much more than my ERJs 55% Full. Even counting per seat. But While I've got 400/750 seats occupied, They've got 400/1200 & 400/1600 seats occupied. I never flew A320s, but when I fly 737s, who are similar, I don't make any money at 35%LF.
Turboprops are cool, but you don't fly them as often, so the leasing cost has to be paid by less flights. And they lack long-range capacity(besides the Q400, a near-cheat plane). There is also a non-economical, practical advantage to regional jets : when lines grow bigger, you can easily replace them with bigger jets. For turboprops, you have to reorganize everything when going to bigger planes(read : jets in the 100seats area). When a ERJ145 costs 15M$ and a Q400 the double, for only slightly superior seat.NM capacity(the Q400 is quick, but not that quick), things are more balanced than a single look at the fuel usage.
And remember : the fuel consuption is per hour, not per NM. Turboprops drink less fuel per NM, sure, but in reality, numbers are not as impressive as they look. Turboprops have their qualities, but don't be fooled : fuel is not the only thing.