For my part, I read reviews with a good dose of skepticism. 

I start by paying more attention to the overall ratings – four or five stars, etc. – when they have hundreds if reviews than when they have just a handful. That's because there are often self-serving reviews, positive ones done by owners, friends, families, and employees, or negative by competitors, that aren't legitimately honest opinion. There's a practical limit to numbers of those, do I like them diluted in larger numbers. 

I also pay less attention to those angry revenge reviews. Don't be so obvious. On the other hand, some are hilarious. For example, including "They wouldn't seat us because they said we were drunk" makes a restaurant review funny, not foul. Who knows, maybe there's a mental health factor too ... reviews as group therapy. 

The constitution protects free speech, including just plain stupid opinions. Caveat lector  (let the reader beware).