Well, actually no, they wouldn't. I thought the same but I was wrong. Everyone who pulls out reduces the future liability and therefore the deficit so the BA pensions managers do not seem to be unduly worried if a lot of people take their pot elsewhere. At least that is what I was told by the experts at BFS.
I am certain that the advice would be to stay with it because of the large contributions made by the company. You cannot hope to match those yourself for the rest of your career. However, as NRA approaches, you should seek advice from an IFA (BFS?) because there are many more things you can do with a pension pot after the new rules come in on 6 April. You need to know about and understand them so you can make the choices which are right for you. My advice would be to go to one of the pension drawdown workshops run by BFS.