Quite so, and the fact that it was never remotely profitable.
That is not correct. BA made a great deal of money on Concorde ops.
It's true that the aeroplane did not pay for its development, and overall it was not a financial success, but the early costs having been written off it was a very profitable aeroplane. It would have made financial sense to keep in the air making profits.
Operating profits (at least in BA.... who knows about AF?) were a reason to keep it flying, not to ground it.