The same thing I think about reviews for restaurants and games. Unreliable. Subjective. Often based on luck and circumstance, personal habit and behaviors. What might bother that person might not bother you at all, and vice versa.
Most places I've worked hover in the large mediocre chunk of the spectrum. Some good, some bad, always tiring as fuck. If you're hard working, well mannered, and keep your head down you'll mostly likely be ok anywhere. I know there are people who think highly of themselves, like to talk shit and gossip, and are petty about the smallest shit. Those people tend to write bad reviews. Truly awful places to work are few and far in between, and the same for truly enjoyable ones. All the advice in this thread is sound: read the reviews, try it out, etc.