There are different accounts because there are differing facilities and benefits within those areas. I understand that it's irritating to have to create a separate account for accessing GitHub, to access the JED, to access the Community Magazine, the Joomla Users Group, the Volunteers Portal (all of these things that I am involved with in various ways, I should add) as well as the forum.
But there are good reasons for having to do these things because the activities undertaken within those areas a very different to the activities undertaken with the forum.
As much as we might desire to have a single account creation facility, with a single sign-on, there are also good reasons for why we shouldn't have that, too. For example, the forum moderators here have the authority to ban user's accounts w.r.t. the forum; should such a ban extend to a user's ability to access the other areas?
Each of the areas I've mentioned—there are others—are separately administered according to their own terms of use.
Nah ... until the day exists that people are somehow biometrically linked to the internet, we'll just have to put up with the inconvenience.
