Your comments

I disagree, 'file' -> 'new'  does create a new, unsaved file, just like in any document editing app 'file' -> 'new' creates a new document. 'File' -> 'new' in photoshop creates a new photo. They all happen to create a new view of the new file of course. 

One would expect 'file' -> 'clone' to work the same as 'file' -> 'new' except it should populate your new file with the content of your currently viewed file. Both would leave you with an unsaved file.

In photoshop, new is in the 'file' menu, duplicate is in the 'image' menu, and a new view is in the 'window' menu (although that's creating a new window, not a new tab). Sublime edit doesn't have a window menu except on the mac, which has the default mac items in it.