Not only is it more dangerous for both the slow hiker and the fast hiker to separate, why are you even hiking together if you don't want to hike together? Don't you hike with a partner, both to assist each other physically - be there if one of you is injured for instance - and for companionship. You lose both of those benefits if you run off.
I ride a bike, and I ride slower than I'm capable of if I'm out on a ride with a slower person. If I'm riding with a faster rider,my experience has been that they slow down for me, otherwise you're on a solo ride. How or why is hiking any different? (Other than it makes even more sense to have a partner than in bike riding.)
