Because the Media Conglomerates who want this, along with Microsoft and the hardware manufacturers *don't trust you*.
The whole purpose of secure boot is to stop you from copying DRM'd media. It doesn't work because the pirates won't use secure boot, and then everybody uses those pirate copies even on systems with secure boot, IE it's completely f***ing useless, except that Linux won't always run with it and Microsoft of course likes that.
If we're not careful politicians will make this insidious crap a mandatory requirement.
Re: why is this needed?
The whole purpose of secure boot is to stop you from copying DRM'd media. It doesn't work because the pirates won't use secure boot, and then everybody uses those pirate copies even on systems with secure boot, IE it's completely f***ing useless, except that Linux won't always run with it and Microsoft of course likes that.
If we're not careful politicians will make this insidious crap a mandatory requirement.