Don't you think you're exaggerating the situation a bit?
I don't see any ultimatum's in your thread. All I see is Helm pointing out your piece as 177 colors, which is an insane amount for pixel art, and pretty much means that it's not, especially for a sprite of that size. However, did he close the thread and throw you out of the forums? No. His reason for pointing it out was because the approach was not benefiting your art, and even went out of his way to provide a great edit. He even said that it didn't need to be a 'pixel purist' piece in the end, so much that the mindset of a pixel purist will help the art, which is true. When you work with images at that resolution, thinking like a pixel artist will benefit you no matter if you're making pixel art or not. The smaller the size, the more individual pixels play a larger role in the overall image people will see. Thus, knowing how a pixel artist would approach an image means you can manipulate these factors to create a better image. Contrast, pixel clusters, dithering, seamless tiling, patterns... knowing how to manipulate these things can only be helpful in the future, even if you're not working in pixel art. I know I've applied things I've learned from pixel art to my sketches and I think they look better because of it.
Also, I don't see where it was said dithering was needed or forced. You can pull off great shading with minimal colors without dithering. Again, the edits do a good job of showing this. I don't see why you're taking such helpful replies and blowing them out of proportion into some sort of negative thing.