Freedom of speech isn't a blanket "call it speech and you can now do it unrestricted" rule. It is the freedom to communicate with interested parties about the matters of your choosing. It is not supposed to be a freedom to perform mass campaigns of dishonesty in economic or political domains.
Sure they could, but it's not the definition of speech that needs to be fixed, it's the definition of "dishonesty campaign."
And there, the problem is not about speech, but identity-protection for the religious. One person's lies are "protected tradition" while another person's lies are "dangerous fake news."
