I agree with all of this, I read into the "single purpose" of understanding the code and complaining about what you don't understand implying that if you understand it, you will be able to point out and comment on things that are wrong /foolish/unsafe/etc after understanding it. From that perspective on the OP, it makes sense to me. Particularly with regard to modularity and factoring; once I understand all of a gigantic PR I will have modeled it in my mind and will begin to either see that it will be maintainable, or will be a total nightmare one day... or somewhere in between.

After a re-read, I realized the claim wasn't "single purpose", it was "primary purpose", in which case this makes even more sense to me. I guess everything else comes from understanding what's in a given PR. It is difficult to find bugs in code that you don't understand, and it's difficult to understand code that doesn't follow convention, etc. I think I've worked this way and just not thought about it from this perspective. I review a lot of code, and what I generally do is fire up my editor in the relevant repo and follow along. If there's a method call to outside of the PR, depending on what it is and what I know about it, I'll pull that up in my editor and review there to make sure I understand what's happening. That understanding is where the comments come from. Maybe "I understand this and it's right" or "I understand this, and it seems wrong because [something]" or "I do not understand this because [whatever]" etc. Maybe "primary purpose" isn't perfect.. perhaps "overarching goal" or similar.. :shipit: