Oddly, most of this brittle nature helps build a more robust product.

That is, yes, it will break often in small ways. However, most of the breaks will be from version upgrades or machine changes. The sooner you find those, the better.

Most issues are because of changes between software versions. Some very few are because of environment, but that's what a staging environment is for.

Honestly, it hasn't been. Probably helps that I run Linux, but would probably do the same on Mac. Managing that extra virtualization layer has always been more pain than just relying on services that are just always there.

It does if you run it inside a Linux VM.

EDIT: Just to be clear, I am referring to the fact that Docker on Mac and Windows runs inside a Linux VM.

My favorite: "We have a dedicated environment for QA. To save time we also use it for production."