I suppose it's always a bit of a crap shoot as to who shows up for a group tour. You might get a bunch of fine folks, with lifelong friendships being formed. Or it could be a bag of ferrets, with everyone ready to kill each other by Day 2. Mostly likely somewhere in between but even so, it would only take 1 or 2 toxic people to ruin the experience for everyone and make the leader's life a torment.
A few years back, touring solo, I crossed paths with a group who were, briefly, going the same way as me. Most of the party were great folks and I almost wished I could tag along with them. But then I met a middle-aged couple, also in their party. Angry, bitter, unhappy people who were determined to complain about ever last mortal thing and expect the tour leader to fix it. What a couple of energy drains they were. If the group leader didn't chop them into tiny pieces and scatter their remains in the desert before tour's end, then he's a better man than me.
Which is a long way of saying, no, I would never want to lead a group tour.