Sure, some of the bad guys could respond to negotiations, or friendly discussion. I'm sure a lot of them would. But there will always be those who won't, no matter what anyone says. Could torture lead him/her to give falsified information? Maybe, sure. But could torture also lead to the recovery of needed information? It sure as hell could. Would you rather have no chance, or some chance? It should only be used as a last resort, but I'd rather have some chance, and I think it's even more morally wrong to let hundreds or thousands die for your personal morals.
Torture can be justified during war. When the U.S. government sanctioned the torture of enemy combatants after 9/11, the resulting information prevented additional mass casualties in the nation, and this is okay. When a soldier in the battlefield is trying to gather information about an enemy's plans for attack, it is okay to use torture to extract that information. All-in-all, in war times, it is kill or be killed. If torture can save the life of one soldier or one U. S. civilian, that is a good reason to use torture.
Terrorists commit such heinous acts against innocent civilians that their basic rights under the criminal justice system should be taken from them. If terrorists are known to have committed acts against civilians and law enforcement wants answers from them such as who they are working for and what was their motive, they should be allowed to torture them to get answers, especially if the terrorists are non-compliant with the investigations.
The only situation where most people would even think torture might be okay is in a ticking bomb type scenario. However, the only result that torture usually provides is the victim telling the torturers what they want to know or hear, just to make the torture stop. It has never been proven to actually produce results that less harsh interrogation techniques could produce just as well
Torture is the act of inflicting pain on others over time. The idea behind torture is to make people suffer. The notion that suffering can ever be a good idea is a very sadistic one. If punishment is the basis for torture, then the punishment should be swift rather than drawn out. If interrogation leads to torture, then the true value of the information at stake should be re-evaluated. But torture is never an acceptable act.