Insofar as Germany is concerned Dusseldorf works because it serves business flyers. All the others bomb because they can't sustain long term traffic. Frankfurt is the only one which would be a success but slots aren't available.
Face facts, the other routes are either crap timings or leisure routes only. Shannon was only put on to drive Aer Arran off Galway and thats FR all over in Irish destinations. As soon as they were out of the picture it got canned.