Because a code review is not to pat each other on the back, it is to inspect and report issues. It is already costly enough without going off topic.

As said, if you want to praise then you are free to do it offline.

This is a professional procedure in a professional setting, not warm words from an encouraging teacher at school... I don't want to have to go through comments that do not add any value to the exercise of finding issues, and I have never seen people leave such comments in 20 years.

> This is a professional procedure in a professional setting, not warm words from an encouraging teacher at school...

Citing a good practice in someone's code as "yes, please do more of this" alongside "don't do this please" is not, in my opinion, fluff.

> I don't want to have to go through comments that do not add any value to the exercise of finding issues, and I have never seen people leave such comments in 20 years.

So only pay attention to unresolved comments?

> Citing a good practice in someone's code as "yes, please do more of this"

That simply isn't the purpose of a code review.

Good practices should be documented externally, so you can check them consistently during code review ;) It's also quite useful to have a checklist when doing a code review.