The problem with the Gutenberg project is less the technical vision than several other things. In no particular order:

1) The market and enduser vision, i.e. the main rationale. Having a clear vision here should have led to a list of features that need to be done in order to get a credible v 1.0 out the door.

2) The lack of consideration given to things like metaboxes which made people feel like the team wasn't thinking things through.

3) The lack of a roadmap with any detail. "5.0" is not detail. We have little to no insight into what features are being planned, what the timeline is, what the minimum features for a 1.0 Gutenberg are, etc.

4) The lack of a strategy for dealing with compatibility. How is this being testing with Divi, Avada, Woocommerce, etc? What about Pods, ACF? What if a site doesn't have a current version of those? What about custom post types?

5) The assertion that this WILL ship live in 5.0 and not have a controlled rollout with life as a beta/RC level plugin (where features are frozen). Given that we're on 4.9 that feels like it's very soon. Speaking of soon...

6) The utter lack of any date transparency. It's one thing to say "5.0 will ship when Gutenberg is ready" but a) who decides what 'ready' means (see above) and b) what if Gutenberg really isn't ready for 12 more months? Will the release really be held that long or will it be shoved out the door? This is exacerbated by statements saying things like the JS framework decision “will likely delay Gutenberg at least a few weeks, and may push the release into next year" when it's utterly ridiculous to talk about a Gutenberg release in the next 3-4 months.

Sorry, core, but this project hasn't been well managed from any of these standpoints and the fact that we STILL lack transparency on the roadmap from both a time and features perspective and that we're getting semi-official statements scattered around the web vs in a central, official place does not inspire confidence.