i have seen many times DarkLord saying that they are not willing to spend a penny on having better infrastructure and security.
How can you wish for a game to have seemless connection for the players and yet say they need to improve their security? DDoSing makes use of similar methods to connect as the players do. To block the DDoSers would also make the players connection harder.
Also, its not the amount of players that makes a problem, its the frequency. DDoSing abuses this weakness (like in any other situation) to create problems.