Care to compare the number of flights cancelled due to job actions, BA vs. Delta, over a 1, 5, or 10 year period?
I'm sure that being a unionized carrier, BA has had their share of cancelled flights. Being a non-union operation has huge advantages.
That being said, I've never been the victim of a strike by any airline. I just prefer BA because I can always get an exit row seat with them, and the inflight amenities have Delta beat.