Because that way I have freedom of movement. No need to have the
hassle of travelling in a group. Otherwise there'll always be
people who want to rest while others who want to go, those who
disagree on the route, etc.
When I'm alone, though, I have complete freedom of movement.
When I'm hungry, I eat.
When I'm tired, I rest.
When I see a mosque, I go in and pray.
When nature calls.... I answer. 
