Back in the day when I was a newbie to Mambo, all of a sudden there was this squirming, wriggling, crying bundle that was the baby Joomla being born. At the time I wasn't new to CMS but was looking for something better, much better (or more user friendly
) than the CMS systems I had tried.
Mambo was going to be it, I was just about to commit when the child Joomla came along, spawned from the loins of Mambo. It wasn't an easy birth. A lot of people welcomed it into the world saying that it's parents were bad parents, but still quite a few people said it was an unwanted child and the parents indeed were worthy. Both sides of the family were upset, angry with each other and the stench of acrimony filled the air.
But still a lot of people said that Joomla wasn't necessary and that the reasons the majority of the Mambo Dev team had split from Mambo were unfounded, they were totally wrong to leave. And, it was suggested that the proof of that lay with the fact that a significant minority of the Mambo Dev team had remained with Mambo and had kept faith with it.
Wind the clock forward from then to now, and the exact same thing has happened, it seems to me;
MiaCMS has been forked from Mambo; more info here http://miacms.org/
I see the same things being said to justify the fork; citing "differences" with the Mambo Foundation. If it happens once you can easily say the team making the fork are wrong. For it to happen twice... well, you make your mind up.
Mambo is dead, long live mambo - and its name is MIAcms
Best of luck to the MIA team.