Springbok:
They aren't shrinking. Yes they dropped one flight a day to NWI, but that's just routine "tweaking" - the kind of things airlines do all the time (often un-noticed!).
You say crews at Bristol are only serving two destinations now - but isn't the key thing is what is offered from a customer viewpoint - which is five destinations from Bristol. The airline has a decent presence at a booming airport, which is no bad thing for them.
Of course expansion and new routes and more aircraft and more crew are what we all like to see, but it's also a very easy way to put an outfit out of business in no time at all.