“No company should be allowed to refuse to give another company millions of dollars a month in advertising income just because they began vocally supporting nazism”

This bill doesn’t do that. It just says that if you engage in “economic boycott” (which about a third of the bill is spent defining, but doesn’t include refusing to deal with a company for “vocally supporting nazism” unless you are using very nonstandard definitions of “vocally supporting” and “nazism”), the State of Missouri cannot use you as a vendor.