There's nothing wrong with having those things, but some games, especially ones with extensive account systems that require personal data to be captured and stored (payment methods and the like), would be be a security weak point if those systems were available to the user. You wouldn't want to expose that data, and you wouldn't want to expose the means and methods of those systems either. And some games, especially the free to play type games, striping out those systems would radically change the gameplay loop of those titles. So you end up with plenty of motivation to not expose those systems at launch, and when it comes time to wind that game down, it's more often than not because a game has failed. So at then end of that games life, you have a mandate for some employees to go through and strip out those features, with a high potential they are never going to be compensated for that task. A large company like EA would obviously pay the employees for the task, but if you have a situation like Fntastic's The Day Before, where the game fails so hard it takes down the studio, who is going to pay the people to make those changes? And if the studio no longer exists, who is mandated to make those changes? The Day Before is a great example because the game is just 100% gone, and it's my understanding that nearly everyone was refunded for the purchase. So who would even have the right to request that the server code be made available, if the licenses had been refunded. I'm sure a few steam accounts still own the license simply because they never filled a refund request, but that number must be incredibly small.
Nothing is wrong with the idea. Mandating games have certain features post launch in perpetuity is part of the issue I have. Video games are art, and I wouldn't want to mandate any artist to limited in any way. When you start limiting art, you won't get paintings that shred themselves, and in video games, you won't get a game like OneShot, where your save file is in some ways permanent, and even finishing the game and starting a new one changes the game. If we are going to mandate things for preservation, are we to mandate that the new game experience in OneShot is also to be preserved for people who already own and have finished the game? Part of the art of that game is that you only have one shot.