Another thought just crossed my mind: if the copyright period would be a mere 10 years, then the Linux kernel up to 2.6.24 would be out of protection and close-sourced forks would be possible. So 10 years would defeat a lot of software licenses.
The only real difference I can think it would make is that set top box that you cant modify anyway no longer has a link to a 10 year out of date kernel.
