Whether you interpret the comment as a smear of the left as you do, or as an explicit threat of violence, as some do, is immaterial. What got people's attention was the open self-description of the current conservative movement machinations, their own Project 2025, as the Second American Revolution. Most Americans are fat and happy and don't want a revolution. And those that do are hopelessly divided on every facet of it(horseshoe theory far right and left).
The issue normies have with this isn't whatever spin either side wants to put on it. It's the fact that he said it at all.