[atomicnumber3]

This is a good point, but I think it's mostly a precondition to having the luxury of the problems I was describing. If you can't even broadly agree on what is good vs bad code, your engineering org has deeper problems. You don't even need substantial agreement, just enough to identify what the genuine problem areas are, vs what's just not how someone would've written it themselves.

[fmbb]

You need to agree on the problem, not the problem areas.

Then someone proposes a solution for the problem, and you review the code to see that it solves the problem. If the solution is not bad and the problem is big, you can let them merge it.

[nasmorn]

I once worked with a guy that thought all working code was good code. I literally showed him a massively improved refactored version and he basically just shrugged. Once he left our velocity went way up