Well, I'm certainly not going to argue against provision of additional flights from MAN to Regional France. Bring them on! But seriously, few cultural tourist destinations enjoy the level of consumer recognition that
Bruges does. There is a ready-made market for city breaks there. Can Brest say the same? Anecdotally, I would suggest that these markets are very different, with Brest popular amongst property-owners and Oostende-Brugge attracting the short-breaks trade.
Remember also that at the start of 2014, Flybe was close to bankruptcy - it may have pulled through the worst of the storm but right now it needs to build cash reserves and demonstrate stability to investors.
[Note: Response to additional commentary added after my initial reply]. David, I think most here are aware of this and bear it in mind. But some here appear to react as if offering citybreaks to Bruges is as crazy as selling package holidays to Saturn. Bruges is a proven old-favourite citybreak destination set amidst a region which offers much more besides. Oostende/Brugge air services are unviable
from the South-East because that region has easy access to Calais ferries and the Channel Tunnel. The dynamic in regions of the UK not served by these is entirely different. Are you honestly suggesting that a twice-weekly DH8D wrapped around the weekend operating MAN-OST would drain FlyBe's cash reserves and imperil the airline? Do you not believe that there are 160 people per week in the North-West who fancy a citybreak to Bruges? We do have some appreciation for culture up here, you know! ;-) Beer and chocolate have their admirers too. And FlyBe is launching new routes anyway, so they can't be too worried.