At the moment, the prices on MME-ABZ make it extremely attractive over taking the train (epecially if you are self employed and your company is not picking up the tab). The extent of the current demand is another question.
For the 6 months in 2017-18 when Loganair went head to head with Eastern, the traffic on the ABZ route was up something like 67%. After Loganair left, it dropped by 43% over the same period.