TamaTown is Bandai's site. They pay the hosting bills. They pay the artist's bills. They pay the programming bills. In order to pay these bills, Bandai needs money. Bandai gets a little bit of money every time someone purchases a Tamagotchi. To entice people to purchase a Tamagotchi, Bandai allows guests to visit TamaTown. If the login codes for non-guest characters are openly distributed, and people stop purchasing Tamagotchi, Bandai will stop earning money, and when that happens, guess what will happen to TamaTown ... Do you want to the the one responsible for sending Chamametchi into a shelter for the homeless?
This is sorta what I was thinking in the beginning guys. I totally agree, my words wouldn't have been so clear.