The airport might be just off the A14, but LTNman's comment is a fair one. The terminal was hidden away and isn't that well signposted.
I would also agree that Cambridge doesn't have much in the way of pax history. Suckling were only there because they couldn't continue at Ipswich. I don't think their scope for pax ops extended much beyond what they currently have.
That said I'm surprised that they are shutting down pax ops altogether. To reference Southend again, they survived many years with a similar model and only one weekly flight. The article suggests they have staff specifically for the pax flights, if so it doesn't surprise me the venture is unviable. I would have thought they could carry on if staff multi-tasked with other roles?
It is also odd that a doubling of the Jersey operation is announced one week, and the plug pulled on everything the next.