I have nothing against vBulletin or IB since I was never a customer - BUT, it makes perfect sense that people disconnected from reality would rework a forum based on the "social media craze". After all, they see the Facebook (ripoff) and figure maybe some will rub off on them! I'm sure untold billions are being, wrongly IMHO, thrown at the Social Media Revolution.
Of course, like any such fad, parts of it are real...but they have been happening all along. If there is anything that has been proven solid, it is that internet users enjoy the standard forum format! All that was needed are technical improvements and perhaps the ability to do better add-ons (and not mess with core, like XF). Better searches and other such features would also be on my menu.
But, as disconnected people often do, it appears they over-thought it. Then, because of their inability to attract real talent (talent does not want to work for companies they don't have a piece of, or feel connected to)...they outsourced the code ala Microsloth, creating a probable hairball.
Of course, I don't know any of this as a fact - just an old tired business guy ruminating. If a company wanted to really do things right, they'd hire me at $250/hr to tell then what they don't want to hear. It would be the best value they ever had. But, having read some of Brisco's blog, I don't get the idea this is a dude who thinks...as well all should...that he is often wrong.