The decision was prompted by the two admin deciding they wanted to move on and become ex ex JWs. They needed the site "gone" for themselves and did not want to pass it on both for personal and practical reasons such as security of other people's data.
That site filled a niche and I think it's a great loss but at the end of the day any forum is the property of the owners not the members. That site was set up in response to Simon deciding to close this one, a decision he ultimately reversed. I don't think the admin the wanted to throw themselves open to pleas to keep it going when it wasn't the right thing for them.