I certainly believe that every citizen is entitled to exercise his rights.
However, I'm not thrilled with forcing police officers to essentially tell criminals, "Shut up and don't confess to this horrible crime."
If a mentally competent adult is too stupid or ignorant to know his rights, or too arrogant to exercise them, then I don't see why my tax money should be spent persuading him to make it more difficult to convict him for whatever he has done.
Yes, I know. Sometimes OCers get harassed by cops. Sometimes good guys have to use force in self-defense and they need to avoid being convicted of a crime. And we have lots of oppressive laws on the books.
But if some punk gang banger wants to brag about how bad he is, I think the cops ought to be free to sit back and listen with a tape recorder running.
At most, a simple statement that you are being placed under arrest (or detained) and that you may exercise your rights--without explicitly listing every right you have--should be adequate. Indeed, I'd happily trade the explicit Miranda warnings before questioning for a general "You are being detained and may exercise your rights" being required for any and all detentions including traffic stops and "man with a gun" calls.