Why does Spy only show a maximum of ten enemy players?
While the ten enemy player limit at any one time could easily be changed, I believe that displaying any more than ten enemy players will make it more difficult for the user to use the information Spy reports. Long lists of enemy players will either take up too much real-estate on screen, or require the introduction of list paging functionality which I believe would make the addon more cumbersome. The limit may be an issue for some users, but it is alleviated by the fact those enemy players who are actively performing actions or who are on your Kill On Sight list will always appear first.