Nor does it convey any confidence that Google will support it.
But yes, I agree, we should have no expectation of support for experimental or beta products.
It is not a joke.
It is a reputation that Google has earned through its actions and inactions.
As shown by https://killedbygoogle.com/ and numerous desperate posts for help [1][2][3] on this and other web sites, Google's "must launch a new shiny thing" promotion culture and abysmal customer service have eroded public trust in the long-term viability of anything that Google creates.
[1] https://news.ycombinator.com/item?id=5523992