Hi there,
CPT is an interesting one.
Agreed - there is no reason to go there outside the summer months from a tourism perspective. However this route is always packed every time that I take a flight there - in every class - there are rarely any upgrades on this route. There is some business out there so that sustains things.
I did read ages ago that there was a BA objective to maintain a second daily rotation to CPT on a permanent basis. Since SAA have removed the daily flight I suspect BA will maintain this second flight on a more permanent basis - maybe for a couple of months in the middle of the South African winter they will just curtail it.....
FD.