He has an interest in getting good devs hyped on S&box, but he's being pretty open ended and honest here. Want to be a game dev? Make a game and ship it... all of the resources for the in between steps are out there and it's only getting easier, but for everyone else just as much as you. I grew up in the gmod mini-modding scene and it's still one of the most impactful parts of my life. First there's editing existing scripts, then there's recognizing what people (or yourself) would like that doesn't already exist, then there's the grunt work of turning it from idea into reality, then there's releasing it with your name attached. It's very rewarding. Still working on releasing something with a price tag attached but this post a good reminder and motivation.

And yeah, the steam workshop was way ahead of its time, and feels like a new, higher tier of sandbox game. I don't think there's any other game that came out around the same time as gmod (2006) that has had comparable momentum and staying power.