In theory, you could set the "itemDisabled" attribute based on the EL-computed length of the selectItem list. In practice, apparently itemDisabled isn't very reliable, and the actual documented behavior doesn't guarantee hiding that item (it could grey it out, for example). "f" elements, unfortunately, are modfiers, so there's no "rendered" attribute"
Probably the most reliable, if not pleasant, way to do this is make 2 copies of the control, one with the "ALL" selectItem, one without and set up their respectived rendered= attributes to display the desired one based on the length of the selectItem list.
Customer surveys are for companies who didn't pay proper attention to begin with.