Do the engineers do a design rotation?
Everybody can't be everything all at once.
I don't think it's trying to promote that sensibility; I think it's about learning, and driving empathy towards the rest of your team. And at the end of the day, the people doing this at Etsy are just changing their photos; they're not doing production-critical deployments (or maybe they are? Maybe some people get inspired).
That's not what the title says. In fact the article isn't even about designers coding. It's about everyone at Etsy coding.
This is really cool! We did/do this at Trunk Club to help fix data issues, though admittedly it's really only other engineers that join in. I'd love to open it up, though. I think it's great to get a feel for how the machine works under the hood.