you need to look at from this perspective=
Jets counter other jets, the 30 minute rule assists the more skilled players, There aren't much players that can win against the more experienced players in a dogfight.
After all enemy jets are eliminated the better players have a 30 minute window before they even remotely get challenged. Or you might find those players who don't focus on the objective and go out in groups with anti-air
if jets ever get added back (which they wont) - 30 minute timer should be removed and we should keep the threshold where players cannot go up in a jet until the other teams are equal. If you see other servers where there are no timers, the jets are way too busy dog fighting each other instead of engaging the ao,