In my experience many execs know what they're talking about.

Where I feel you may see real variance is ethical and capability standards: willingness to stick to a line, and competence in analysis and execution based on what is known. Sometimes, hidden agendas can be misread as lack of competence, ie ethical lapses cause actions that are misread as capability lapses.

Knowledge alone is less often a factor.

Of course this varies widely across companies. I've been fortunate to work with some excellent folk at executive and C-level.

Here, an exec clearly (a) understands or can make a clear, direct assessment and (b) was willing to do so in writing. Kudos on both grounds.