Why? DM called it exactly correct. Just watched the post match press conference and i thought he was brutally honest and see no reason to call for a change in management. He lost his 3 best players for that match and no team with the size of Aberdeen's budget and could expect to beat a Motherwell team who are pretty decent and very difficult to beat ( we have struggled this season with those 3 players).
It's not exactly rocket science calling Motherwell long ball merchants. That is how Motherwell play, long ball up to big strong centre forward and pick off the second ball. That is what they do, it aint pretty and wont work all the time however if your relatively strong at the back then it's adequate for the Scottish Premiership.