Have you tried this recipe? I have changed font size from 22 to 11, it improved the appearance, but on MC restart it set the size back to 22.
Yes, it seemed to solve the problem for me for the brief period when I was using a device set to 200% size. (Surface Pro 2)
However, setting Windows' size to anything above 100% does not seem to be affecting Media Center's size on my desktop machine.
I wonder if it's going by the device's "native" DPI, rather than what has been set.
Is this a client by any chance? (connecting to another library) If it is, I suspect the reason it's returning to 22 is because it's set by the server.
If not a client, try setting it to 6 instead of 11.
Also some icons are still tiny, including expand/collapse triangles in the tree and icons in the Options dialog.
You need to restart MC for everything to be scaled up correctly - which you obviously can't do due to the issue above.
Plus it would be good to read the DPI setting from Windows and set the skin sizing accordingly (http://msdn.microsoft.com/en-us/library/windows/desktop/dn280510(v=vs.85).aspx).
I would have agreed with you until I actually had a display which was natively set to 200% size.
Everything was far too big, and I had to reduce it to about 125% to balance the amount of content I could view with the size of everything on the screen.