Originally Posted by simons1

You have answered the question yourself then. The aircraft was late out of maintenance, late to the gate, late to depart and no doubt the cleaners were expected to do a deep clean in 5 minutes, motivated by their love of BA and the minimum wage.

Not saying it's right but there are no margins for manouevre at BA these days.

Originally Posted by NWIFlyer

I imagine because maintenance areas need to be tightly controlled for both safety and security reasons - and the cost of putting a trained, cleared subset of cleaners into maintenance bays just doesn’t make any sense when the work can be done in a dedicated area and another plane put into the maintenance hanger - which is called Dynamic Resource Allocation.