Basically, if a BIG ship turns up, I know it will be nigh impossible to bring down unless there is a sustained organised attack force. However it also means that lolwutting nubs that think that a big ship should be the world and more can't ruin my day with flismsy abuse of the power of their expensive hulk. They may have to learn to actually aim!
You can't have everything - where would you put it?
Some of the missions are tough, though - I'll grant you that. As in - ridiculously hard.