I've reduced my flying on Emirates substantially over the last 12 months or so.
The main reason... the cost. Most of my flying is for personal reasons, so the cost comes out of my own pocket.
The cheapest economy fare from MAN-DXB is now over 500UKP. I don't mind paying a premium for a direct flight, but that premium is now over 300UKP. I can pick up a flight with Etihad or Qatar for far less than the Emirates price.
You can also get some pretty good fares on Silverjet if you're prepared to fly from Luton. I've just booked a return for 820UKP. Silverjet fly from a private terminal at both LTN & DXB, so you can avoid the mess that is the main terminal at DXB. Also, you get a 30 minute check in time if you're pushed for time.
Cheers,
Rick