When people invest a lot of time and efforts on a project and do not get financial compensation for it, ego clashes can get to very ugly proportions.
There are a few motivations to work on an open-source / free software project :
1 - Learning / Research : This one is very strong in academia (obviously) and among junior / hobby programmers. Experienced programmers also tend to join projects to learn specific ways of doing something or to develop new techniques. Unfortunately, it is not enough to drive a big project very far as big parts of it wil not be cutting edge nor particularly interesting.
2 - Attachment to the project / community : The people that stay with a project after the learning / research phase usually fall into this category. They have learned a lot and often matured a lot with the project and can now produce great work with minimal ego problems.
3 - Financial compensation : Your employer pays you to implement something that will be integrated into an open source project. Lots of very good code comes from this, as paid coders are usually very high grade and tend to check their ego at the door and concentrate on getting the job done. A company will often hire one of the top develloppers of a project and allocate them specific amount of time each month to work on it. Red Hat is known for doing this, surely there are others but I can't remember any specific.
4 - Pursuit of fame : Some people dream of being the next Bill Gates for obvious reasons. Other people dream of being the next Stallman, Wall, Knuth or Torvalds for equally obvious reasons. They join interesting projects, do a lot of work and take a lot of space inside the community. When 2 or more of these types meets, ego clashes can occur. They also tend to polarize opinions and often divide the community into clans of supporters. This is the kind of situation that usually leads to forks.
It is important to note that altough Forks can lead to very interesting and beneficial technical development, they almost never occur for technical reasons. Sometimes after a fork, both projects enjoy prolonged "anarchy" or deorganisation period and notwithstanding the time and efforts lost, can lead to the demise of both projects.
In this particular case, both protagonist look a bit shady, especially Robbins as this is not the first time something like this happens.
Registering the domain names for something you have shown zero interest for when you are aware one of your long time collaborator has views on this market is a jerky move at best.
Technologically, we loose nothing and have a lot to gain, especially in the GCC cross-compilation development.
So long live both projects and shame on you people for having such big egos and poor social skills.
EDIT : typos