I do not agree with a lot of the person's ideas here, but it was a fun read. And I will give them that
Big
Snake-like
Flight
Breathes fire
is primarily how I'll visually recognize a dragon. You can differ from this template, but I'll probably always recognize it as a variant drawing from this.
And I do also personally dislike dragons shapeshifting, especially into humans, and sorting dragon personality by color, though I could not say why. It's always interesting to see someone I disagree with have a few opinions that resonate with me.
Overall, I think this person is very much a fantasy trope traditionalist: stick with the established dragon stereotype and don't move too far from its spirit; while a lot of people nowadays (including myself) like playing with it much more.