I don't even understand why this is a problem. If you wanted to get into Warrior's channel that has a password, you pm Warrior and ask him for the password; just as you would any other channel in the teamspeak.
Besides, league is a game based on teamwork and communication. You lose a lot of that survivability from lack of communication because randoms are talking louder than the people in your game. Think of it the same way you would with Jailbreak. If you're in the Jailbreak channel and you're trying to listen specifically to the people in your game and the cts, would you want a crowd of people joining and just talking about every single meal they've eaten in their lives? No, it breaks your concentration and a lot of the time, you can't hear orders, which inevitably gets you killed and renders your presence in the server pretty pointless. That's why it has a password. Even more so because it's a community channel, which was paid for, and can have that privilege.