Google deliberately opened up dart development early. I thing that was a good thing. They could have kept it closed and released it today, it's roughly as mature as type script seems to be. Would you have been happier with that?
Yes. Google (and others) need to stop releasing half-baked products.
You release something half-baked, even if it gets up to speed down the road, people will still have perceptions of it being half-baked. The above exchange is typical.