Some windows don't resize, which is why the resize option is greyed out. That isn't a bug, or an accessibility issue really. Windows are allowed to tell the window manager they don't want to be resized. Most windows do still allow resizing and I kind of prefer things to allow resizing, but it is fine for some applications to decide that they will just create a window the right size. You can file bugs against them if the content doesn't fit when you have specified large fonts, or if they request a size bigger than a netbook screen.