You made valid points and I can agree with most of them. What I don't agree with is having the never ending story. ALL things must end. That's just the facts of life. DMD was a lengthy story, just like Grandma's House currently. The fact is, many stories start out as either short stories or novellas but as time goes on, the writer/creator begins to add more things to make the story complete. Many times it's due to the creator's imagination. There's usually that speculation factor that's the cause, (what if he/she does this? What would happen?) and so on.
Then, in the case of these "games" (not all of the things posted in f95 qualifies but I addressed that before in another thread), you look to your fans/audience to give you inspiration. Some work out, others don't. Either way, you push on based on the results. The danger of stretching out the story is twofold. 1) Inevitably, the creator/author runs out of ideas and gets bored. They have new ideas, for new stories and they begin working on it before finishing the original. That happens all of the time, it's called "writer's burnout". It doesn't mean that you didn't like what you put out, it's just time to move on to something fresh. It's like sleeping on linen. It feels comfortable but, eventually, you have to change them.
The second danger, and it's more applicable here, is that, you get stuck on where you're going (called "writer's block"). You listen to the critics, start following their ideas, then you go forward. Now, along the way, the story drifts from your original concept. For those who depend on subscribers, when that happens, you start losing support. You try to bring them back by listening to the whiners, "add this/that, don't add this/that". Pretty soon, you're trying to appease everybody and the story starts getting out of control.
Tom Clancy wrote a number of mega novels that were between 700-1300 pages. He beautifully wove a number of them, based on One character, to tell a grand story which, basically covered the character's career. The problem was that, while doing so, he branched off to tell whole stories about support characters that fans loved. That would have been okay, had he wrapped up the main character's story but he did it while telling ancillary stories. He had to add elements to the secondary stories to make them relevant to the original. Pretty soon, those stories began to suffer as they quickly ran into dead ends. Meanwhile, the original story that started the whole shebang, was nowhere near where it started.
I firmly believe that, if you're going to have a story, you need to have a definitive end. Writing instructors advise 1st timers to have an outline. You put down what you want to tell; the elements in which to tell a story, your pro/antagonist(s), your conflict(s), and an ending. That way it can't get away from you and you don't have to depend on outside sources to finish it. I'm writing a story online currently that's been several years in the making. I constantly have to self edit to make sure that it stays coherent and the scenes are relevant to one another. It AIN'T easy!
The other point that I disagree with is telling two versions of the same thing. For reasons explained above, it's not very feasible, Especially when you have to spend so much time rendering. That's how stories Quickly get away from the main concepts, with both versions winding up being poorly executed. The Best idea is to do the story how you envision it, then Tell it that way. You can use an Occasional suggestion if you think it will help, but if you stick with your script, you can tell your story with satisfaction. You'll ALWAYS have your naysayers and bitchers, that's the way it goes. Humans, especially entitled ones, will always have a gripe. Humanity can't survive without them. The best thing to do is to tell a story the way You want. Please yourself First. If you do it right, mass fans will follow, just like Clancy. If you do it wrong, you try to learn from your mistakes for the next time but the bottom line is do it for your own satisfaction first. Ultimately, it Is Your story to tell.