not everything can be discussed, but it was explained (in that link, it is explained very well):
- it is easier to organise related work into teams (for example: iceberg, libgit2 bindings, filetree and now tonel) than to have everything on same team.
- is also a marketing stuff: more groups of pharo related stuff in github.
- it is also an easy choice: if that does not works, is very easy to change and group everything (but today I still think it was a good decision)
Esteban