If you were to imagine something like `component-bower install`; it would work for local apps, but your app would no longer be a component since it depends on non-component things. This ultimately makes it hard to use in other components and you lose modularity. If you don't care about modularity and just care about a package manager for monolithic libraries you're probably better off just using bower in the first place.
In other words, it's probably easier to just fork the bower repo and add a component.json.