The IT/Business divide is something that exists in most businesses I've worked with. I think it comes from a few different drivers, one of which being that IT is often the smartest set of folks in the room academically if not socially. But one piece I can't agree with is that the fault for the divide lies on both sides.
Lets flip away from IT for a moment and concentrate on other "support" parts of the organisation. HR and Finance. These aren't the front-line of the business but they are critical support functions. Now I've regularly heard people in the business moan about Finance being too conservative or too controlling but I've never heard people talk about a Finance/Business divide or that the CFO is disconnected from the business. The perspective might be that Finance has a different view on the current opportunities or issues but not that the business and Finance are disconnected. HR even more so, the HR Director who is disconnected from their business is a fired HR director.
In IT however I've regularly seen CIOs who are disconnected from the business and seen architecture communities who have said classic phrases like "it doesn't matter what the business wants, if we say its not going in, its not going in". IT continues to talk technology rather than business and optimise things (programming languages) that add zero business benefits. IT regularly bleats "The business must realise how important this is" rather than actually working out what is important to the business.
The business/IT divide is the fault of IT because IT doesn't make the effort to communicate the value in the language of the business its like the worst kind of tourist who thinks that shouting louder is better than learning the local language.
Its time for IT to stop looking inwards on optimising wheels and start focusing on how to communicate about IT with the business in their own language.