They only rebranded the consumer side, and that was as I recall coincident with their move from being a 'cable company' to pushing bundled IP services. The business side is still branded Comcast. I don't think they much care about their reputation, at least not enough on it's own to rebrand. In many of their markets there isn't much in the way of an alternative other than the at-least-as-shitty AT&T.