>>23453513
I think it's more like they don't want to accidentally cause a reactor explosion that close to the ship. Earlier in Unicorn OVA episode 2, Full Frontal snipes a ReZEL that was taking off from the catapult deck, and it tumbles out of control before exploding. The explosion was massive and still close enough to basically vaporize most of the Nahel Argama's left catapult deck and render it useless for the rest of the OVA. Zaku explosions in 0079 were potent enough to create colony hull breaches already, so it's a decent concern.