As a qualifier to my experience, I've been assistant organizer on a few meetup groups for easy day hikes but am not in the hiker-leader league of most of you.

My biggest problem was people seldom showed up. I'm reading the experiences on this thread and thinking, "Wow, how did they get so many people to show up?"

When I decided to start a section-day-hike of the Florida National Scenic Trail I posted my intentions along with required abilities (mainly the ability to walk 10 miles without undo discomfort, a few other things) to see if I could get any hike partners. Two people responded. Neither had ever walked more than 3 miles in their lives and wanted to sign up for a 12 mile excursion. I refused them both as even if they did show up (doubtful) I was concerned for their physical well being.