Support. I only have a single row of friends at the moment, so adding another page/row could prove to be useful to me in the future.
Or they could just have a "Next Page" button that pops open another identical gui, with different people ? Instead of the whole /friends1, /friends2 thing...
add pages, so on the bottom right and bottom left, there might be this item which represents a "next page" and "last page" icon.