[anomie]

I used to worry about this too, but finally concluded that me not understanding it was in and of itself grounds for rejecting that review. 90% of the time well structured code (and tests, and good comments, etc etc) should be enough on their own to make it easy for me to understand. In the rare cases when the nature of the change means that's not enough then people ideally provide any additional explanation in a note accompanying the review (or in a crucible comment). (In practice I reckon most of the time these explanatory notes probably belong in code comments anyway.)

We have a very strong culture of constructive code review though - I guess you might have some work to do to get those more experience coders to get into the mindset that would accept this sort of feedback in a positive way