The problem is that B&N probably can move right out. Maybe not today but soon enough.
In general terms, one cannot p*ss around with big companies. Many politicians have discovered this to their cost. The company just moves to another location. They tend to not have great emotional attachments.
I have visited the B&N factory ~ 2 years ago (on a tour) and I think their biggest real activity was the Cirrus assembly, which involves shipping almost whole airframes to the IOW by road+boat, so there is little advantage to the present location. I would not mess with them if it was me.
I also know that an awful lot of people working on the IOM commute there on the ferry. For any given company moving to for example Lee on Solent, only a part of the workforce is going to be sorry.