How so a similar situation?

You have known many professors who are going through reporting a fifth of their class to the deans for cheating? You know how they feel and act during that event? Really?

I firmly disbelieve. I spent 9 years in a university setting, knew a lot of professors, and I personally knew exactly nobody who went through that. And from what I know of human nature, and the likely emotions that someone in that position would feel, I very strongly suspect that your judgement of how they would react is completely wrong.

Can't help if you choose to twist my use of the word "similar" into "same".

I've been through multiple stop-te-cheating lectures and each time, the professors went out of their way to appreciate the non-cheats and minimize negative impact on the innocent due to the actions of the guilty minority.

Anti-cheating lectures aren't similar. The thing that caused problems here was a mass of effort spent going against specific students. Was that also the case with your professors?

Indeed. The stress associated with individual confrontations is orders of magnitudes higher than the stress associated with giving a general anti-cheating lecture.

For what its worth, in the one class I've had where the professor did catch a fifth of the students cheating in the first midterm (and immediately handed everyone Fs), his mood towards the rest of the class changed similarly.