Well, it's a bit complicated. This site is owned and funded by Stardock, the makers of Windowblinds, DesktopX, ObjectBar and a host of other apps. HoverDesk is created by another company and is a direct competitor of Stardock (notably with ObjectBar and portions of DesktopX).
Since skins hosting is a form of product support and promotion, it makes little sense that Stardock would pay for HoverDesk's promotion and skin hosting.
So, I wouldn't say HoverDesk is being ignored, just handled appropriately in a business sense. BTW, I'm one of HoverDesk's developers and we completely understand Stardock's position.
Your best source at the moment for HoverDesk themes is
http://www.deviantart.com