They fixed that

In AutoCAD 2012 I could use the mouse wheel to zoom in on a detail and, if I got too close, zoom out one click and zoom in one click, and the detail would be just a bit smaller on the screen. It was an excellent use for the mouse wheel.

AutoCAD 2013 fixed that. Now when you zoom out one click the detail gets smaller, yes. But then when you zoom in one click, the retail return to the same size it was before you zoomed out.