It just wasn't ENOUGH of a time-saver. Speed from takeoff to touchdown was wonderful, but that wasn't sufficient; From Manhattan to Montmartre still required surface transport, baggage check & claim, airport surface congestion, and other queues that seriously diluted the speed advantage of the Concorde.
Well.. Leaving Paris at 12:00 noon and landing in New York at 11:00 AM seem to be a pretty good time saver.. A lot of business people could make the trip to the US and back in 24 hours.
As it looks today, the speed advantage of non-supersonic aircraft is even more diluted than before, given the fact that security is tight and mass transportation, inevitably, causes congestions.
The last time I flew to Geneva, the plane was taking off from Roissy CDG. I spent an hour and a half to get there (rush hour)and another hour and a half waiting at the airport, The flight lasts about 45 minutes.. Total three hours and forty five minutes. Add the trip from the airport to Geneva center --15 minutes-- and that's four hours flat.
Slower than the TGV high speed train that takes you from the center of Paris to the center of Geneva in three and a half hours.
No waiting, no security, leg room, bar, scenery..