It's tricky to compile this sort of information, because the data changes so frequently. It's not an impossible task, but it requires continuous updating and lots of research. Think how often you read about brand X being purchased by investment company Y, and then sold again to Z. It's a jungle out there, and the end result must be reliable and accurate (or else, what's the point of trying).
In an "open edit" format (where anyone can contribute, wikipedia style) it should be feasible. But again, it's not easy.