The split usually isn't 0.x (not ready) and 1.x (stable). Instead it's 1.x (established enough) while working on 2.x, then 3.x, then ...
The way I read it, the post seems to argue they have enough users already to seriously consider cutting the first stable release.
Is it 1.0 yet?
The whole point of not being stable yet is so that you can try things out and see what actually makes sense before committing to it for all time.
(Counterpoint: C++, JavaScript xD)
I guess it has been like 10 years at this point though.