[davelnewton]

At the same time, if standing up for code quality implies a "fight" then there are several issues, only one of which is the actual code quality.

CC does matter, even if in a limited sense: the more that can happen in a chunk of code, the harder it is to reason about. I guess I'd always thought that was obvious, because it's the same way with everything. Dismissing it out of hand is disingenuous.

That said, metrics matter at different times, and in different ways. Sometimes things are just complex at the method level.

In any case, if coworker is disregarding input, there's a systemic issue at the personal level. I hope you're just using hyperbole when you say the only course of action is a fight: that's an extreme escalation pretty early in the process.

If the coworker disagrees with the opinion, why not just have a conversation about what both parties mean by "complex"? List the tradeoffs that are being made (e.g., deep vs. wide) and why making or not making them makes sense.

People can discuss differences without "fighting" in any sense of the word. If they can't, they shouldn't work together, because it's stupid and a waste of time.