Totally. Blamestorming taps focus and ultimately progress towards "how it should be"

Wouldn't it be more efficient to focus on what's wrong with the code then, rather than whose fault it was?

Very few things are as black and white as pregnancy.

When solving a problem starts by blaming someone, it can distract the conversation and attention to become about personalities, positions, politics, arguing over perceptions, & interpretations, instead of the problem itself.

If, after something like the 5 why exercise, all roads keep leading to someone, one can probably look at having a positive supportive intervention.

If that person doesn't want it or feel they need it? That's more of a culture thing than just about one person.

It depends. Mistakes happen, sure, and you just say "it was a mistake, let's make sure we have the processes to catch it or avoid it next time and move on".

However, when there's one guy who always keeps making mistakes and creating work for the rest of the team, even making the same mistake multiple times, then, in my opinion, some blame is warranted.