My friend thinks gold damage and kills are important stats and get toxic if DPS doesn't hold them

So I got a buddy that I play with who starts talking shit to the DPS when he has gold damage or kills as Rein or whoever. Also if our team is not doing well he immediately starts blaming the damage. How can I convince him that damage isn't everything? What are the convincing arguments that the scorecard stats aren't really too meaningful?

Edit: Thanks for the insightful comments. Now I can tell him why tanks can easily get gold stats and why DPS not having them isn't necessarily a bad thing. Hopefully this will lead to less toxicity.