The original post was on 2012-09-21 and still no resolution. Not to mention, as others have pointed out, it's for a cert that expired several months ago. But this link is public acknowledgement of the issue and it's still unresolved as of today. Regardless of bureaucracy, that should be considered highly unacceptable for the largest consumer ISP in the United States.
Look at the dates on the posts in the thread. He gave them a month before coming back and chastizing them again to find out they'd closed the ticket without fixing it.
This is pretty damn pathetic (1), that's all I can think to even say.
Probably. Never underestimate the bureaucracy of a big corporate entity (specifically when it comes to having to pay money to fix something).
Possible causes:-
* General ineptitude
* It's not something they monitor.
* The main www site is up, what's the problem?
* The technical contact for the previous certificate is no longer at the company. So the "expiring soon" notification was never received.
* The PO is awaiting 'approval', or Finance are sitting on it whilst arguing whether it's CapEx or OpEx, or the "Business Justification" was rejected by someone who doesn't understand, etc, etc.