Based on your specific complaints, it sounds like your opinion doesn't matter in this case; you're not the audience. You want support and a predictable future: you're looking for a product, not for technology. This isn't a product, and it's not a platform.
If instead you represented another company looking into solving this same problem yourself, and are looking at starting points, then you're the perfect audience. In that case, you'd have time and motivation to contact the developers directly rather than gripe on HN. You'd be less interested in whether there was an organized community, and more interested in how to directly influence the roadmap. You'd care about what the code looks like, how they solved Problem X and Problem Y, that kind of thing.
First, "guarantee" is the wrong word to take too literally here. Depending on how you want to look at it, there are no guarantees, even with guarantees.
But looked at more loosely, answering that is really Uber's responsibility. Why did they release it? If it is just a PR release, fire-and-forget works fine for that.
If they want to see wider adoption outside of their firm, there are some fairly obvious things they should do to foster that. Sometimes you release just the right thing at just the right time and everyone else does your evangelism and support work for you, but it is much more normal for your next great thing to take a while to build a user base.