But, you're wrong.
The top rated post on Hackernews right now is a bunch of people gushing about how cool it is to see the source code for the Apple II LOGO language[0]. Your code has value beyond whether or not someone is going to pick up a new game-dev trick for their next title. It's a window into how games used to be built. It is a tiny composite piece of gaming history, and history is not just about how Mario was built, it's also about how small games were built, and what trends across the entire industry looked like.
Your code has value beyond just publicly releasing the source. Maybe you would never revisit it in a million years for a million dollars, but the overall gaming industry is interested in remakes and remasters right now, and if you've ever worked for a publisher or sold the IP rights to one of your titles, it is not out of the question that the publisher might want to do a remake without you. That's the entire premise of this article, and if you have the source code, even if it's not portable, even if it's using hardware-specific hacks, even if it's written in an obscure language, your publisher will be in a better position than if you didn't.
To be kind of blunt, this attitude is exactly what I was getting at above. Game devs don't understand why they should even care about history. If your takeaway is, "I don't care about old games unless they make my new PS4 game run faster" you have missed the point. If your takeaway is, "archival only matters if my game is successful, and I don't know if it'll be successful yet", you have missed the point.
I completely, 100% understand that game dev is stressful. Zoom out a bit from that; working in the games industry in general is kind of hellish right now. If you're putting 80 hours a week into building a game for (on average) less pay than you'd get as a general software dev, and you're not doing it because you genuinely care about what you're making... that's a stupid career choice. And if you do genuinely care about what you're making, then try to make sure it lives longer than you do.
Bear in mind, what I'm asking for doesn't have to take much work. You don't have to go crazy building out your source-code in a special way if you don't have time. Change nothing at all about your dev process -- just take 3 minutes when your game ships, stick your raw source code, assets, and a DRM free binary on a flash drive, and then mail it to Jason Scott.
That's it. Just by doing that, you're now ahead of most other companies in the games industry right now.