If Apple is such a technology leader and so on the cutting edge, then why aren’t *they* trying to converge the tablet & the desktop interface?
No, tablets are for content _consumption_, whereas desktops are also useful for content _creation_.
Microsoft is killing itself.
Why would Apple want to converge two incompatible user interfaces? I certainly don't want Gorilla arms. Touch screens on a desk top are a bad idea. Mouse driven on a tablet is a bad idea. The iPad succeeds because it is FINGER Multi-touch driven graphical user interface, the mouse touch pad metaphors for the desktop with graphical interface made the desktop succeed. Apple knows not to fiddle with success.
Given that, Apple is converging what are excellent ideas from both interfaces. Many disagree what exactly those excellent ideas are.
As for your consumption/creation wall, you really don't know what you are talking about. I am several hundred pages each into two novels written entirely on an iPad. Photography, shot edited, compiled, and published, 100% from iPads! easily doable. Presentation, with collaboration with multiple colleagues. Also easy. Vide? HD 1080 P. . . Shot, edited then uploaded to the web. . . The only thing lacking is the ability to burn disc directly from the iPad. Creation and maintenance of spreadsheets? Yup. Doable. The one thing that is currently beyond iPads is development. . . but CONTENT? No problem. Don't believe the propaganda. Other make tablets are just consumption devices, except for Windows quasi-tablets cum laptops cum table top Surface machines that really don't know what they are.
Microsoft is killing itself BECAUSE it is trying to do what you suggested. . . Converge tablet and desktop interfaces. People hate it in both.