Unfortunately there are many sites that are like that. Many of the designers of these site can not afford to maintain the site any longer or the models that they have up on their site are only up for a certain amount of time (before being replaced by new ones).
This is one of the many reasons why Zealot is hosting so many different designers collections. The GREAT thing is, as a member of Zealot, ANYONE has the right to have their collection hosted here (if they so desire), and not worry about their work being lost. Not only that, but they still have full control over their work and at any time they wish to take it down, they can (without question or hassle).