Operational reasons
Operational reasons - this could mean
"We are cancelling your journey because we will not make a profit on this flight and it is much easier for us to consolidate a few flights together as this will make much better use of aircraft and staff resource. We're sorry if you don't like this but hell, we know you have no alternative -if you did, we wouldn't be able to do this -and it is what the flying public are now used to, thanks to Michael O'Leaky. So, have a pleasant few days of unexpected ( bonus) time in London."
Remember the above when you get the obligatory " we thank you for choosing BA and flying with us today. Your custom is valuable to us and we look forward to welcoming you aboard again in the future "
Fat chance! Bye, Bye, BA.