I believe the key aspect to watch in here is how open the communication is in the team towards the 'boss' and the other way around.
Finger-pointing is never good, however, from a management perspective, if one of your developers falls into the same issue several times, it might be time to step in and try to help him overcome this repetitive issue (e.g John is not testing properly the code: 3 production bugs in the last 3 months, let's give him a checklist so he remembers how his code is supposed to be and how he should test it).
From a development point of view, 'blaming' is already incorporated into a mainstream tool such as SVN, therefore I really don't see any harm in going "John, please fix that piece of crap you wrote" and putting a name next to it. JIRA also incorporates the name of a person when you file a bug (however the field it's not really meant for the person who's responsible for it, it's pretty much so that someone fix it).
Here's the thing though, as many mentioned above by many, if a bug arises, it's a shared responsibility: from developer, to testers, to QA, to managers. If your boss at some point handles an angry client over the phone with things like "I'm so sorry, John never tested this properly", then I'd definitely be looking for another job. A good boss should go "we'll take care of this". No names, no finger-pointing, just solutions.
Again, I believe it's all about communication. Perhaps the only thing your boss wants to do is see who's having troubles in the dev team, or what kind of problems the team is having (perhaps for training sessions?), but I don't think you will find out exactly what's behind his decision (or better said, we posters/readers) unless you talk to your boss and your entire team.