Because IT and ES have no business credibility. They're seen as the keepers of email and sharepoint, a tactical partner, not a strategic one.
Business analytics belong in the business. Like many other business processes, it is enabled by technology, but that doesn't make it an IT function. Accountability for strategic decisions and demand forecasting must remain with the business unit. Not only could IT/ES NOT do it-- they SHOULDN'T have to do it.
ES has positioned themselves as "not the business." They're perceived as "those technology guys." What a lost opportunity for them.