As of today, if you create a custom view (which is required to customize asset columns), you cannot delete anything you have created. For example I made a typo on of our custom views, it can not be deleted.
You can create/modify a view but no delete. Please add a delete option.
Its possible to delete a custom view, you can hover on the view which will display modify and delete option to the right hand side of the view name.
I noticed this after I posted. I didn't see it originally because those icons are hidden until they are hovered over with the mouse. They should be there permanently in my opinion.