It isn't your fault people are focusing on the wrong stuff. I think that video and your explanation does an excellent job of showing what's important. In fact, the stuff about the foot work and seeing it exaggerated has helped me realize a bit about the throw that has been eluding me for a while. I don't think that anything you did on the video was wrong, it's just not the line that most people want to throw. Pointing out what makes it more of a "distance" type throw (mostly minor body position things, all the important stuff is still the same) just helps illustrate what people should look for as opposed to what they do look for right now.
My understanding is that while we call that a "distance" line now, it was probably a lot more common 15 years or so ago. That was the only way to get a disc to go that far, so it was called a "drive." IIRC, there's a video of Avery Jenkins hitting a ace with a really similar line using a KC Pro Aviar. He seems to think it's a predictable and useful enough line.
The fact that people rag on you for your reach back and body position, but that you can throw a putter 400' is a great illustration of how people focus on the wrong stuff. It's all about the hammer pound. That's the secret to throwing far. It's not about reachback, it's not about the x-step, it's not about the line your throw. It's all about the hammer pound. All that other stuff will help make incremental improvements, but throwing really far is all about the hammer pound.
I also really like that it's a putter you're throwing and that you're emphasizing that you'd do the same thing with most other discs. All the important stuff you pointed out applies to driving all discs. Now people won't get hung up on your disc selection. They just happen to be getting hung up on other stuff instead.
I don't want you to get discouraged, it's a step in the right direction.
What would be really interesting is to see that exact same video, but with you throwing a putter shot that doesn't turn over like that. It flips to flat and stays that way. You'll probably get like 50' less distance, but it would be cool to show what changes and what doesn't. Spoiler alert, most of the important stuff he pointed out either won't change or will be less exaggerated.