Is a persons life worth only 6 1/3 years?
I wouldnt say that is the question at hand. More like, what is acheived by locking someone away for much more than 20 years?

If you still want to draw some correlation between existent dutch law and nonexistent american law thats fine, but I dont remember this topic being about the US.
Forget Law for a minute, im talking about what is practiced here. If there were no retarded and/or minor people being executed in the US, then I would not mention it. However, the fact remains that these executions STILL take place EVEN, after the federal government ruled it against the 8th amendment to execute the mentally retarded (and the execution of minors is still perfectly legal in 19 states..)!! That is a massive failure of the judicial/legal system, and seems to me pretty (to borrow your phrase) "screwed up"! The Legal system itself breaking the laws...