[erpicci]

Going back to the original question, one more point for having an antivirus for GNU/Linux is that a lot of servers (mail server, file storage...) run this OS, and antivirus software enhance security.

For instance, anyone may send to a Windows user an infected file (trought a GNU/Linux SMTP sever). If the server has an antivirus, the malevolous mail won't even reach the Windows user.