Being a slow out of shape rider myself heres my take:
I dont wany anyone behind me pushing me, I am already pushing myself to the max and thats as fast as im going...any faster and im going to have a heart attack or pass out.
Go ahead at your own pace and wait every so often or double back around every so often so you can keep moving, but dont get behind me saying "lets go, you can do it"etc...all thats going to make me do is turn around and go back down the hill and go home and never ride with you again!
My girlfreind who is faster then me on the climbs knows better then to hang behind and "root" me on. We start out together and about a mile in she is gone and i dont see her until we are back at the car an hour or so later...totally fine by me.
When I ride with my buds they are gone from the beginning but wait at the top for me so we can bang bars the whole way down. yeah they wait for 10 minutes or so at the top but they like the rest...
On a better note I actually passed somebody on my climb yesterday on the uphill and made it stick...I have never passed anyone on the uphill and usually get passed by bikers, hikers, joggers, walkers, snakes, turtles etc...so i was stoked, but I still couldnt catch my girlfriend.