I suspect it stems more from the Google origins than anything else.
Most of Google's code base is one big repository, and everyone is working at HEAD. It's nice not having to support a matrix of dependency versions, but that really only works when you can also modify downstream dependencies with ease.
That works within Google because there's a culture of constant maintenance; but out in the real world, you can't expect OSS package maintainers to be constantly active & willing to accept patches.
Yes, you're probably right, it does sound like they work this way internally, but it's not really practical if you have an open ecosystem with lots of different packages by authors who are not paid to maintain them. It'll be interesting to see if they bend on this and adopt some versioned solution.
Most of Google's code base is one big repository, and everyone is working at HEAD. It's nice not having to support a matrix of dependency versions, but that really only works when you can also modify downstream dependencies with ease.
That works within Google because there's a culture of constant maintenance; but out in the real world, you can't expect OSS package maintainers to be constantly active & willing to accept patches.