Two thoughts:
1. The outgoing CIO, Beth Jacobs, was also their Chief Content Officer. Given her background [1], and the fallout, I'd suggest she was hired for the content side of her job, not the traditional technology-centric CIO skill set. She was promoted in 2008, the same hear the now outgoing CEO came in. I didn't find a connection, but my guess is the CEO brought in the CIO. If so, he's responsible for the mis-hire.
2. Beyond that, I think we'll see more of this: CEOs wouldn't be able to pass the buck on poor technology decisions as easily as they might have 10 or 15 years ago.
[1] http://articles.latimes.com/2014/mar/05/business/la-fi-mo-ta...
Sure, it's part of the CEO's job to inspire confidence, but what's nonsense is that virtually any CEO would be responsible for any single tech-vulnerability down the line.
So, it may well be that investors expect that, which would mean that the nonsense is on their part. And, perhaps Target is simply responding to that nonsense, but it's still nonsense.
Said another way, it's not ceremonial if it matters. But, it is nonsense that it would matter.
Personally, I think it's good that the CEO has lost his job over this. It's the sort of incident (along with the cost of Sony's breach[1]) that can be used as a cautionary tale pour encourager les autres to take security seriously.
1: http://www.zdnet.com/blog/btl/sonys-data-breach-costs-likely...
http://money.cnn.com/2014/04/30/technology/security/target-c...