That is thinking out of the box, something that military forces have great difficulty doing. Number 2, 4 and 5 quite publicly caused a collapse in the victory of the first Gulf War.
It is too bad that there are not more Soviet and Russian WWII movies overdubbed in English, because the NKVD and the KGB really mastered this stuff back in the 40s and 50s. Not in all departments of the organization but in enough of them to become the masters of the Cold War.
1. We lose the moral high ground.
2. We give the enemy recruitment material.
3. We justify the enemy torturing our guys.
4. The enemy will fight much harder if they know that they'll get tortured if captured. They will be far less likely to surrender / capitulate.
5. Winning the peace after victory will be much harder.
6. The intelligence you get is likely to be crap anyway.