I'll bite, or nibble. Not really horror stories.
I've had some disappointing trip partners. But I also thought sometimes I needed to change my approach too.

Needing to be more clear that we were sharing work around camp and I wasn't just being bossy.
Two guys were experienced campers, but canoe camping & fishing were new to them. They got jealous if they didn't catch fish like I did. Pouted if I didn't help clue them in, and thought I was bossy if I did. In later years they went together and each called me to complain about the other guy.
Another guy was great company but never did any camp chores either.

I also learned not to be too helpful and encourage trippers to look to themselves instead of me for help.
Sometimes I created a dependence. Instead of learning, I taught some to just expect me to be there every time for everything. My most recent trip I just handed the guys a map (he likes maps). Told them where we were going and let them go as slow as they pleased. They only got lost twice and found their way again each time. Great learning experience I thought.

It's also good to keep your trip options open and include others in the options available. Same guys on my last trip just couldn't go all day, every day. Even though they said they wanted to fish and see new country, they just weren't up to it. If we traveled, they were too tired to fish. If we stop to fish, they said they wanted to see more. I let them know I wasn't stopping them and they needed to decide what they wanted to do.

I'm sure others have had similar experiences. Nothing new. Some guys are one and done. Sometimes I just need to do a solo trip. Cause my casual pace, is someone else's race pace.