-1
The Sticky Jumper/Rocket Jumper were banned in Jailbreak because they were being used to waste everyones time and emptied the server out three times.
They allowed Guards to completely avoid rebels and never die by jumping over everyone, this especially became a problem on the space map, as players could remain in the air for a very long period of time.
As previously stated, we had two occasions (from Guards, one from Prisoners) in which the server was emptied - which caused the change.
In an arena gamemode like this, in which there is no ability to simply capture a control point and win or do some objective, we need to limit the amount of time wasting that can happen (this is the same reason why Last Guard Kills All exists).
Because the server is arena, the longer people are dead they are exponentially more likely to leave, especially if they can see there is 5/6 more minutes on the clock and people are wasting time.
Edit: I should mention this was in combination with the BASE jumper, allowing even more evasion and time wasting.