Why does vncviewer use ssh -L?
 

After studying ssh -L, why does vncviewer use ssh -L to foward a local port to connect instead of vncviewer just uing a normal ssh name@server?

becuase -L is how you forward a port. just sshing directly won't help, unless you're thinking about X forward and the likes, which is not what this is about. this is for generic TCP tunneling for security.