The only way I see it looking more or less attractive is capturing airfields by landing a supply plane on it after elimination of all the opposition. This is the good old Warbirds gameplay mode.
Otherwise only ground forces should capture territory (or a flag). Fortunatelly now we have an ingame Mission Menu and players or officers can command ground forces which flag to attack and issue other commands.
I hate CTF how it is done in RoF for instance, i.e. flying around a flag

When I first saw it in RoF beta I deleted it immediately (came back only in 1 year, yes it hurt that much). But that's me
PS. Just imagine, each player is given one tank which he sends to capture some flags. Players would have to cooperate to to achieve success and cover their group of tanks together. It could be a fun sandbox mode.