Why should we create another complex markup language, instead of using hyper-links and images/buttons that are already there? Too tired to type?
I don't think is complex, I think is very usefull. A trigger to an object I want to share.
Think of Instagram, in a comment of an another user you want to show a pic you made of the same subject: Hey @user check my ~objectID looks similar
When the user start ~ Instagram will return the thumbnail of my pics, I can choose the one I want and bam I've created a direct link to one of my pics. Same goes for Twitter and other apps.
Sure there's other things to think about how it could work in Instagram but it could be an idea.