BuddyPress.org

I don’t understand why they didn’t just model it from their own awesome member theme. Even the skeleton member theme is more or less the same as the default.

It’s because the awesome member theme was a customization of the default theme. The default themes have been around since BuddyPress was first made available as a release candidate.

So, as Nicola and DJPaul suggest, if you want to create your own custom themes, by using either the skeleton theme or the default themes you have a solid foundation from which to work!