the process of getting a dead-end subject to talk through torture sounds far more reasonable than being nice to him.
It sounds so, which is why people do it, but it isn't actually the case. Torture, in the end, is likely to produce one of two results: either you break the subject's resistance to the point where they will tell you whatever they think you want to hear, or it strengthens their resistance and they dig in, accepting the pain until it kills them. The latter is clearly useless, and while you are likely to get the truth somewhere in the former, it is going to be mixed in with tons of useless or incorrect information, all of which you'll then have to spend time and effort attempting to verify through other means - means which themselves are sufficient, making the torture unnecessary at best and a waste of time and resources as you chase false leads at worst.
It is worth keeping in mind that most terrorists don't think of themselves as evil - they think of us as evil, which is why their acts against us are justified. When you capture one and torture him, you are reinforcing that viewpoint. When you instead treat him well, spend time talking with him about yourself and types of experiences you and he share, you instead are showing him that you are human too, that maybe you aren't as evil as he'd been taught, and that maybe what he was doing wasn't as justified as he thought it was.
Consider Hitler's miscalculation in the Battle of Britain - he thought that bombing English cities would devastate the citizenry's willingness to fight. Instead, it made them even more dedicated to the war. Hurting someone is not a reliable way to gain their cooperation.
This was also my reaction upon learning more about it, as I used to have a similar view (horrible but potentially necessary) myself.