My preferred toolchain and stack just works better on a native linux box because it doesn't need virtualization overhead when I'm on a linux box. Those efficiencies add up pretty quickly. Since I mostly do backend dev work macs have never worked for me as they should.

To address your point about this being a recent trend I actually noticed the mismatch when I first moved to the bay area 5 years ago. It seemed weird to use a mac as a dev machine and then deploy to a ubuntu box in production. There was always some issue that came up because whoever was doing the deployment didn't verify things in a VM first and then had to do some firefighting on a production box.

This wouldn't be a problem if workplaces gave you the option of getting a linux box or a mac. At most places you don't have a choice. All the IT management software is built for a mac so you get a mac.