Sadly, Cyrano, you are correct.
It's a pity that the airlines don't cater for the pax who, for the extra comfort, want to fly Business Class at their own expense. For me, when on medium to long haul leisure travel, it's comfort and not ticket flexibility which takes precedence. After 30 odd years of the hassles and traumas of staff travel (seen it all - done it all) my wife and I now choose to PAY (!!!) for peace of mind and comfort. We choose airlines that can fulfill our requirements. When they fail to provide what they advertise I think that I am justified to feel short changed.