Appeals might as well be a “redo” if the appellate court decides the issue at hand tainted the trial.
Why not permit the defense to propose a clearly unjustified theory if he’s guilty as sin? That would only get unsympathy from the jury. In the meantime, everyone else’s jury trial rights will not be chipped away at by example. If I were on that jury I might say that I cannot constrain my thoughts to what the judge ordered, and so that if I believed “entrapment” happened I would be conscience bound to vote not guilty.
>>Why not permit the defense to propose a clearly unjustified theory if he’s guilty as sin? <<
Two words: Casey Anthony. They snuck their alternatives through the back door and it worked.
Every direct argument needs a legal and factual foundation. It is just the way the law works.