Agree completely with this. I love the "mark and sweep" aspect of Inbox, but after a couple of months with it, I think I have to go back to the old interface.
What's weird is that if you try to create a label called "Important" in Inbox, it will say it already exists. Yet it doesn't show that label as an option when creating bundles. It's like they went out of their way to prevent you from doing exactly what you're suggesting.