When I want to detect a compromised system, I can easily boot a different system from a safe media. This is easy and much more reliable than relying on secure boot features.
> Yes, ideally, you will want to only run perfectly secure applications with perfectly secure configurations and be a perfectly competent administrator.. but we know that is not going to be possible.
Still, even insecure applications can be sandboxed by the system, so that the harm they can incur is very limited.
As long as remote malware is easily able to delete all my files or upload them on RapidShare due to buggy applications, I do not really care if the rest of the OS is compromised.