Because people trade to buy battleships. Because trade is the backbone the game. Nothing to buy, no trade. No trade no pirates. No pirates, no lawfulls. NO GAME.
Hence since battleships are shit and you die in 5 minutes against bombers that are so close that can you hit them sometimes but can't really lower their shields the frustration builds up and you give up on all the time spent on trading for that battleship and leave. Just look at the player count stats. So NO GAME