Creating the initial community requires the first person to create ems of other people who do not initially exist within the simulation and organize their society in a way that makes them productive and prevents them from undergoing value drift. The first person must also prevent value drift in themself over the entire time period that they are solving these other problems. This is far too hard for one person and organizing a group of uploads that can do so is nontrivial.
Creating the initial community requires the first person to create ems of other people who do not initially exist within the simulation and organize their society in a way that makes them productive and prevents them from undergoing value drift. The first person must also prevent value drift in themself over the entire time period that they are solving these other problems. This is far too hard for one person and organizing a group of uploads that can do so is nontrivial.