But I think the critical mistake it makes is not copying the VSCode extension API 1:1. I don't think Nova has the spread/appeal to cause people to develop (complete, high quality) extensions.
The core editor is important, sure, but the extensions for VSCode make it what it is for many people. When your implementation story for them is rougher, it's going to suffer.
I wound up just sticking to my old-school Vim workflow due to the above. shrug
VS Code is a wonderful piece of software and if it works for you, that’s great. But not everyone likes VS Code or the design choices that led to it. Software makers shouldn’t be criticized for wanting to break away from those choices entirely and do something new or different. That may very well mean less community support or third party extensions - but every piece of software doesn’t need to be the most popular to be impactful. You probably won’t find a lot of developers coding in Light Table these days but when it was first released back in 2012 it brought some new and interesting ideas to the IDE space; I want more of that, not less.
Panic wants to sell a product that doesn’t have modern legs - a text editor simply isn’t too remarkable in 2020, although Panic sets a high experience bar. The extensions matter and the product is less without them. I think it’s totally fair to criticize.