I don't really like Dtube. It doesn't work properly in my browser unless I use a chrome incognito window.
Even then it takes forever to upload.
And when reading a post you don't see the video included, like with youtube. There is always the "click here" necessary, as far as I know.
However, unlinking is not an option. Dtube is just an app that runs on the steem blockchain and has nothing to do with steemit. What the app does is actually upload the video and afterwards create a post. This is standard behaviour, and not something you can easily change.