It would appear to me, that if any of the groups mentionned, namely: security, fire or ATCOs strike, in sufficient numbers, the airport would be unable to function as a commercial airport. I suppose technically it could operate as a unlicenced airfield for a small amount of GA without fire or ATCO, but security would still be required. Commercial flights coul not operate without ATC, so the fact that it is apparently only they who are holding out, does not mean the airfield will be able to operate.
Egnt999 I don't think you would bore us with your stories, they might help us understand why employees feel as strongly as they do.