>To teams who are using it in production, did you talk about this? What are arguments for using it despite it not being 1.0?
The main argument is that "1.0" is an arbitrary number (semvers or not).
There are hellish unstable and buggy projects on version 4.x and stable, production-proven projects on 0.x.
Not to mention projects that when going from 2.x to 3.x or so, decide to just rewrite everything with new APIs and incompatible changes (of course semver allows this, but as it's also often accompanied by core devs abandoning the 2.x version, you're left with either an EOLed codebase or a breaking-changes rewrite).
The main argument is that "1.0" is an arbitrary number (semvers or not).
There are hellish unstable and buggy projects on version 4.x and stable, production-proven projects on 0.x.
Not to mention projects that when going from 2.x to 3.x or so, decide to just rewrite everything with new APIs and incompatible changes (of course semver allows this, but as it's also often accompanied by core devs abandoning the 2.x version, you're left with either an EOLed codebase or a breaking-changes rewrite).