> So yeah, it wouldn't take him a whole lot of time if he really wanted to change the license by removing all the others' commits and rewriting it by himself.

Good point. I may try to get involved in its development as well to spread that out a little more.

> Also, what does AGPL has anything to do with keeping the license open sourced?

The AGPL requires that any code linked to it also be distributed with an AGPL license (the difference from the GPL being that hosting over a network counts as distribution). Every part of the project is technically linked to itself so if someone makes a change, no one else can use that change in the project under a different license.