i dont know the exact reason...but my educated guess would be that it cut down clan (server) costs as well as made things easier to maintain...also, although it is a good map, it was and wouldnt have been as popular as the others
The Palermo server is actually what became the Sniper Server. Additionally, Palermo was simply not able to be kept constantly full and just did not do so well for us. Therefore, we got rid of it. It is a good map though.