I think the main problem with starting direct long haul routes into Asia from Manchester is the stiff competition you're up against. You've got the following hub airlines going East: Emirates X 3, Qatar x 3, Etihad x 2, Turkish X 2, Oman Air, British Airways, Pegasus, Lufthansa, Air France & Swiss etc.
Price, frequency, timing, Air Miles & product all play a big part. It's a hard nut to crack. I was critical of Juneyao to start with for their meager offering out of Manchester, but the more I think about it, the more their strategy makes good business sense.