Ryan,
Why should this annoy you?....... Are you financially vested in this site?
What people sometimes forget is that when a site is started, its done by one person or a group of people that invest time and money into it. When that site gets really big storage can be a huge issue and in some cases become expensive depending who hosts it. At some point those owners may decide to take other actions such as temporarily close the site, what till the month is over to let the storage and bandwidth monthly cycle renew...i.e. ...BT, or shut it down all together.
Then you have the people who are Administrators, Editors and/or Moderators who invest themselves deeply to bring you a platform to better your art. Think these people might get tired of it as well or want a break from the financial and time demands. Its a lot of work to run a forum/site and it amazes me that so many do so willingly to help better the art.
So unless your making a donation to this site or have some other stake in it, why would you feel that this site should be up and running for your own edification? Don't get annoyed...look for other alternatives......there are many. Enjoy each site you visit and take what you can from them, nothing lasts forever.
A short list (listed alphabetically) of some of the ones I frequent that have good content and are unique in their own right.
AoB
Ausbonsai
Bonsaistudygroup
BonsaiVault
BonsaiNut
IBC
KoB