Making Games on Your Own as an Engineer
I don’t think it’s bad advice but having shipped multiple (really bad) games, I think it misses the two biggest/best pieces of advice I’ve gotten:
1. GDDs are probably a distraction if you’re a solo dev - prototyping and grayboxing a <i>lot</i> and looking for the fun mechanics without any art/music/story to get in the way or distract is essential 
2. If you’re truly just starting (and don’t already have a sense of fun), absolute best way to start is to carbon-copy a game you find fun, then start adding/tweaking elements. 
This both builds the mindset required to make games, and helps you get into the “fun iteration” loop quickly without getting bogged down in writing a lot of interesting technical systems that don’t end up contributing to the game in a meaningful way.