Author is posting honest and respectful critique of Zig features on their blog. That is a valid way of collaborating in the community discussion. The project github isn't the only place where discussion is allowed to take place.
Make blog posts, it's great!, but if you don't think you're the expert then they'll go a lot farther for everyone if you put 5% of the work of doing so into engaging with the community about it for additional insights first. That's a fair note to make, though I agree the ending could be less passive aggressive about those who don't want to engage with the community.