With SourceForge putting ads in installers, they're no longer a good option. This leaves GitHub in a monopoly position, which is worrisome. Especially given the terms:
"GitHub, in its sole discretion, has the right to suspend or terminate your account and refuse any and all current or future use of the Service, or any other GitHub service, for any reason at any time. Such termination of the Service will result in the deactivation or deletion of your Account or your access to your Account, and the forfeiture and relinquishment of all Content in your Account. GitHub reserves the right to refuse service to anyone for any reason at any time."
That could be a problem if GitHub's investors want more revenue generated. We need some way to distribute open source projects so they're on at least two services simultaneously, synched.