And why would such an airline as KLM want to operate in/out of a "skin of the teeth" airport such as Sheffield City, and with restricted loads, when there is a full size "Sheffield" airport just up the road and around the corner?
KLM does not want to operate to DSA, as it is quite satisfied with its service to Humberside and does not want to dilute that. Apparently there have been a lot of discussions over the past few years with DSA management trying to attract them. The lack of a service to a hub airport is one of the reasons DSA has not performed as predicted.
When Easyjet had a 'half-base' at DSA, this necessitated a daily service to AMS, and the load averaged about 80 on a 319.