hmmmm... I've never really thought this thru before... typically if I'm waiting for someone, they're newer than me and I'm riding with them to help out... as they catch up I call out KEEP GOING! I don't want them to lose the momentum they've got... and I can catch them since they're slower anyway...
when I'm with friends it seems like there are always times when someone will have a burst of energy and pull ahead, then slow up... I just keep going and vice versa... we never get that far off from each other and always end up together anyway... I have never, ever thought it was rude for someone to pull past me... heck, I'm usually either cheering them on... or jumping on to draft 'em!
There is a fine line between "hobby" and "mental illness".