I don't see this as gatekeeping. I am all for writing your own engine as a learning experience. Most programmers I have worked with have done so. I am all for

I don't see this as gatekeeping. I am all for writing your own engine as a learning experience. Most programmers I have worked with have done so. I am all for sharing your learning experiences in a blog post. A lot of really good blogs do this while being really honest with where they struggled and what they learned. See https://jvns.ca/ https://jvns.ca/ for a prime example. My problem with this post is that it's a post by someone very inexperienced presenting a very shallow and narrow view of what a game engine is in a surprisingly authoritative tone. If the article would have been "I made my first basic game engine, here's how it's structured" I would have felt differently about it. But this is presented as "this is how a game engine works" and it does not present an accurate image of that.