I have no problems with the number of riders, or the speed of the ride....
I have a problem with anyone that violates the intrinsic nature of THAT ride. If there is a large group, COMMUNICATE. Let everyone know the ground operating policy and then stay within that framework. Problems can be fixed, but arrive with an unserviced, rust bucket that is falling apart, NOT COOL! When riders expect others to continously bail them out, even when months back their i.e. puncture repair kit should have been sorted when shown back then...
When Mark and I ride together, we have a general idea of what we are going to do, and then we just ride, for the pleasure of riding, enjoying the environment, taking pics, resting under a tree if we feel like it.... our rides are extremely elastic, and the direction can change 180* in a heartbeat... there is no-one else to object anyway and I LOVE riding like this. It is far more spontanious and, I feel, rewarding. We also communicate with locals, and the places we have found because of this are really stunning...
If the ride has a modus-operandi, for 5c, stick to it! If we ride at 8, then we blimmin ride at 8. ("I got lost going to the meet spot" is not good enough, it shows total disregard for the rest of the group, and a level of unpreparedness that translates to other things)
If however, you accept riders on YOUR ride, then you are responsible for them, and do what is necessary to get them through everything. If you fire them off the ride, make sure it's from a location where they can safely return home. At least try and teach them how and Adventure Rider thinks and behaves...
And I can't stand the sound of someone 'Hawking' and spitting! That is just grose.