I understand that the final nail in the French Concorde coffin was the another near disaster after the Paris crash. An AF Concorde made an emergency landing in Halifax with very little fuel. This was after shutting down one engine and then not noticing for too long that they were still losing fuel from that engine:
http://www.pprune.org/jet-blast/8207...g-halifax.html
Following this, and another few incidents, AF could not take the risk of another Concorde disaster so they decided to ground it, and then went on to have a few disasters with other aircraft e.g AF477, Toronto B777.
I also understand that the French quoted BA £50M a year to maintain the design authority for the aircraft. This happened to exactly match the BA operating profit for Concorde, coincidence?