The short answer: security. Here's why:
SSH: Providing shell access to a server by logging in to the command line can open our server up to security risks.
CGI: CGI scripts are vulnerable to a large number of exploits used to compromise the overall security of the web server. They are often vulnerable to remote execution exploits, mainly because of inconsistent coding. CGI can also interfere with server performance because a new process is started every time the CGI routine is called. This uses memory and other resources on the wserver, which in turn slows down the server's response time.
SMB (Mapped Drives): A web server is no place to put your departmental files, especially those with confidential information. Personal storage space is available through HSU’s Network Folders. Staff and faculty can use mapped shares for file storage; departmental shares can be set up by ITS.
While you should update your publications and other printed materials as soon as practicable, the old URLs (with the tildes) will automatically redirect visitors to the new site until October 18th 2011, at which time the old URLs will become inactive.