I don't think this is a fair criticism. Postgres only has 7 core contributors - and influxDB is far less complex targeting a much simpler use case.
Furthermore, hundreds of people have been responsible for its development over the years: https://www.postgresql.org/community/contributors/
As an additional, possibly more relevant example - the Cortex project has 158 contributors: https://github.com/cortexproject/cortex
My larger point is that, in contrast with the new project, InfluxDB currently has ~400 contributors. I'm certain that many dozens of those were involved in getting the current storage engine to a stable place. And now that hard work is on a path to being deprecated by moving to a completely new language and set of underlying technologies.
Taking the project from a handful of contributors to a production-ready technology within an existing ecosystem is a non-trivial task. I'm sure it will come together eventually, but the commitment to ship it "early next year" seems unlikely to me.
We're also building on top of the work of a bunch of others that have built Arrow and libraries within the Rust ecosystem.
When the open source GAs, I don't really know. But we're doing this out in the open so people can see, comment, and maybe even contribute. Who knows, maybe after a few years you'll be a convert ;)