I think that when speaking about small teams or individuals you are generally correct - it is generally faster to skip step 4, and always branch from step 3 to step 5. But like everything, there are edge cases: sometimes assigning blame actually does "help solve the problem". I would totally agree with your comment without question if you had written the first sentence like this:

FTFY>>>Step 3(assign blame) is unnecessary if and only if assigning blame doesn't help solve the problem. A pragmatic will realize this, and skip step 3 when it is unnecessary to assign blame at that point in the process- you get to the solution on step 5 faster.

Upon careful reading of your comment, I imagine that this is what you meant, but some people will read your version and imagine that you are saying that "assigning blame generally doesn't help solve the problem". It's the problem of [logical AND &&] vs the English construction [ , and ] which can mean the start of a new semi-related clause. Note that I did try to hint at this in my description of (step 2) - Do we need to assign blame "at this moment"?

Completely agree with your second sentence.

One specific edge case for small teams or for individuals - the process of assigning blame can reveal toxic team members (one of which could be you). Getting rid of a bad team member has the potential to speed things up radically.

In large organizations, assigning blame can often be done in parallel with fixing the problem. I would imagine that the benefit of the fix would generally outweigh the benefit of the blame. However there can be good reasons for management to demand that you offer up the scapegoat(as opposed to a sacrificial lamb) before your team gets permission to fix a problem. One of them is the small team edge case that I mentioned.