Brian, it wasn't that we turned down the idea - we did consider and discuss it, but we couldn't find a way to make it work well for this year. As Rosy said, the problem is finding people to lead.
Consider this - we had 69 people registered this year, a number of them riding solo, so a conservative estimate puts that at about 35 trikes/bikes. Assuming 10% of those didn't want to join a group ride, we still would have had about 32 trikes/bikes to plan for. Even if we limited each group to 8, that means we would have needed 4 lead riders, all of whom would have to be comfortable leading that size group. The smaller the group, the more leads we need; the larger the group, the more difficult it becomes. Few attended from the area, so whoever was lead would have needed to be able to learn the route quickly, have the map in front of them, or have a gps. So in short, before we can consider a sign-up for group rides, we need to have a sign-up for leads.
Please be assured that we welcome everyone's thoughts and suggestions, and we do consider them all, even if we don't end up acting on it!! Also, this particular topic isn't dead in the water - we consider and discuss this every year, along with everything else that needs to be planned, and we will do so again over the next few months. We want to make these gatherings a great experience for everyone who takes the time to join us!