It's not just the UK that's struggling. US carriers are having a bad time as well.
Son went to Boston with BA last weekend for a convention. He came back on the daylight with a connection to home in Newcastle. Plane was on time. No baggage and connection cancelled. He picked himself up, filled in the lost baggage report online while on Heathrow Express and caught The 2000 from Kings X. Bag turned up 48 hours later. Not ideal but he's done enough travelling (since he was a child) to know that you there are times when a bit of personal initiative works best.
Colleagues of same son went on United via San Francisco to Seattle. Plane late from London, missed connection, one bag missing, next flight only had one seat (for two people) next available seat 24 hours later. They decided who should take the one seat, the other went standby (and got on).
It's going to be like this for a while yet.
BA do seem to be making a bit of a meal of the problems though.