1. There’s no good and elegant way for a scientist to march. For one thing, there are no slide projectors. In fact, there are really no tools for marching, except the bull horn. And that takes someone who wants to talk loudly. Duh! Scientists don’t actually do things. They get tools to do them.
2. Scientists marching in America would look too French. Guillotines are for frogs and mice, not people.