This seemed mostly dismissive and patronizing and manipulative -- meaning, that is how op treated his underlings.

Part of that is because their idea of venting is inherently just a worker being a spoiled brat or unjustifiably disaffected.

The point of the advice here seems to be

How to get thru your 1on1s in a way that tries to leave a generally positive impression on all the folks who hate their jobs

Which is most of them

For the purpose of helping op earn that next promotion

All that said

I hate 1on1s

I don't think I have ever gotten anything of value from them except to know with more conviction that I needed to bounce

And I'm guessing the manager has gotten the same impression

I suspect 1on1s could be useful in some way to the org or manager or employee

But I doubt it