I disagree, I believe that all opportunities should be made to negotiate with terrorists because it weakens them and divides them.
If rebel/terrorist leaders have spent the last 10-20 years telling their recruits and their supporters that you are the devil, the great satan, the infidel, the worst thing ever to walk the Earth, and then they sit down at the table to talk with you, what does that say about them? The true believers, those who swallowed all of the propaganda over the years, may very well see it as a crass betrayal by old and tired leaders who want to cut a deal. Their supporters will also see it as a sign of weakness and a backing down from the revolutionary message.
Additionally, you can use peace talks to drive a wedge into a rebel movement and cause some to disarm, others to walk away completely, and others to form their own ultra radical groups with far fewer members than they had before. Think about what the British did with the IRA.
The talks don’t have to go anywhere… Offer terms that the elite/leaders cannot possibly accept but that many of their supporters would be willing and ready to accept, this will further alienate the leaders from their supporters. Simply negotiating doesn’t mean you will reach an agreement. In the end, you will have the moral high ground because you attempted to resolve things peacefully and they refused to accept a deal that the media will declare was reasonable and fair.
Always talk/negotiate with terrorists, always.