First of all, I do not see this from any character's eye level, I see it from actual combat military experience, and, whether anyone chooses to agree or not, what was going on in Sunnydale at that time was most certainly war, and Buffy and the others were the army that was on site to face the First Evil and its minions. It was completely fine with everyone for Buffy to be the one in charge as long as that meant that she was the only one doing the fighting and bleeding, and as long as the risks were taken by her while they sat all warm and comfortable under her roof, behind her closed doors.
Then, suddenly, the Potentials have to start sharing in the pain and the danger, and they are ready to elect, or more accurately appoint, a new leader, a leader who they knew next to nothing about. (Incidentally, I have no ill feelings for Faith for taking command once it became obvious that Buffy wasn't going to stay. She was the next logical one to lead) I find it ironic that, after the first time that Faith leads the others into battle, and the casualties that it incurred,(while Buffy's own plan, returning to the vineyard, had proved successful) leadership of the group went back to the very person who they had rejected in the first place.
Being the leader of an army means that you sometimes have to send your troops to their death. As Wes said when he was the leader of the Pylean insurgents in Season 3 of "Angel," the decision sometimes boils down to sacrificing a few so that the majority can live. The fact that Buffy regretted those losses was obvious, but just as obvious was the fact that they were unavoidable, based on the information that Buffy had to work with. Caleb "had something that belonged to her." As far as she knew, that might have been a Potential, or several, or, as it turned out, the very weapon that she needed to win her war. Certainly, as Giles pointed out, it could just as easily have been a stapler, but it was Buffy's decision, as leader, to make, and she made it. The Potentials were, as far as we know, free to leave anytime they chose to do so. There were obviously plenty of vacant houses available by that time.
That isn't to say that Buffy didn't make mistakes in this matter, because she most certainly did. Before announcing her plans to the entire group, she should have met, privately, with Giles, Willow, and Faith (Spike and Xander being absent at the time) to explain her plans and discuss specific strategies, and be sure of their support. Once that was done, she could have presented her plans to the Potentials and Wood, along with an alternative for anyone who chose not to agree: an open door, and sincere well wishes on their trip through it.
No one in their right mind wants to risk their lives, not for any cause, regardless of how noble that cause might be. And no one in their right mind wants to send others to die. Sometimes, however, it becomes necessary to do either or both. Buffy's decision to return to the vineyard was the right one, and she was, ultimately, proven right in that decision. But because of the lack of support of her "friends" and troops, the risk that she took in proceeding with that plan was increased tenfold or even more.
