I think it all goes back to a fixed vs growth mindset, and we both know the clear winner here.
When I was a teacher, my peers would also complain endlessly about all the observations and walk thrus performed in their classrooms, and how they felt like they had to be on their best behavior when they were in the room to avoid comments and criticisms.
I NEVER understood this logic - so you are pretending to do things in a different way to avoid getting comments from the observer?! No way, never me. I also taught and behaved exactly like I would when they weren't there. I wanted the feedback. I wanted to know how I could improve to be a better teacher for my students. I recognized I didn't know everything about teaching and was open to change if it meant doing things better, smarter, and more efficiently for my students.
Of course the caveat is that the observer has to know what they're talking about from their proficiency and experience, which wasn't always the case, but I'd still give the benefit of the doubt to anyone with more experience than myself to at least give their comments a shot. And from what it sounds like, you also have the right experience to provide strong, actionable feedback to improve your workforce.