[iajrz]

I see your point, and I agree that it's good to be nice to people.

But being in leadership and spending time around a few hundred coders over the hears has taught me the value of someone who does this.

I hope this wasn't the reason the person was fired, because it's a missed opportunity for management: someone with that kind of drive and commitment to quality is valuable to have - and hard to find. I can count with my hands the number of developers with that kind of drive I've found.

With no further context - meaning: I'm making a lot of assumptions here - I think I'd've helped them schedule time to evaluate these opportunities for improvement (how much do they cost to fix? how much will they cost if not fixed? How can we prevent this from getting in new code? etc.), and when the numbers are right - schedule time for fixing them, too.

If non-agreeableness was their sole defect - it could've been worked on over time. That's what leaders are there for: to help their collaborators grow.