What would you do, dilute the First Amendment? There is already a process in place for dealing with things like this.
First amendment is applicable only if both manufacturer and the reviewer are in US. So for a lot of cases it is not going to be applicable e.g. what if the reviewer was in Hong Kong in that case do you think first amendment is going to be even applicable?
That is why a framework is needed which then could be agreed and imposed upon both manufacturers and reviewers, just like your various standards e.g ISO.
Regards,
Audio_phool