If BA pilots decide to walk the picket line, it will certainly mean that other airlines in Europe will capitalise on this disruption, and the result will be that BA will lose market share, quite likely, permanently.
Does anyone really care?
Certainly not most passengers, they will simply fly on some other carrier.
And, perhaps liking the service better on that other carrier, not return to BA.
It will serve BA, their weasil-like CEO, and the malcontents on the FD right... most of these folks will continue to find out the hard way that grand airlines are no more...and will never return.
Ever.