As was stated earlier we are conditioned to delays and specifically delays and cancellations on domestic flights. I too dislike the crowing about how much time has been saved when delayed over an hour on a flight that 20 years ago was just 55 minutes and is now scheduled at 90 minutes
But the main issue today is the absence of competition on domestic routes. Back in the days of shuttle there was British Midland and a very public competition on who could deliver the best on time performance. I can say with confidence this made BA focus intently on domestic punctuality.
In the absence of competition for the foreseeable future the delay compensation on U.K. domestic routes should change to 60 minutes. That will focus the mind!!