Not a reason, but you can point out that they are relativly unregulated in other countries . This whole suppressor business is a US thing thanks to Hollywood. In Finland, they encourage them on ranges and when hunting to protect hearing. They are over-the-counter in France and available as a firearms accessory in Germany. Here's a pic from Walther's site:

http://www.carl-walther.de/englisch/...efense-55.html