WordPress admin panel is a very unpredictable environment for such a complex product like Visual Composer. Because of that, we decided to remove Backend Editor in 2.0 version and focus our development on Frontend Editor. As a result, you as a user are getting a more stable and faster editor. Release cycles will become shorter and new features will be delivered to you faster.
To justify the “loss” we will introduce new “structured view” mode in Frontend Editor (similar how it was in the Backend Editor) and there is always Tree View mode available (a layer style representer and editor of your layout).