Well, if you're talking about a 4.4 restaurant, they are probably meaningless. There's probably a couple of TRUE negative reviews in there.

If the restaurant is a 3.1, then yeah, try to find a different place - there IS hair in the food, the cockroaches are real and the waitress DID stick the hotdog up the you know what.

Is this really a thing? I know that I'm much more likely to share a negative experience and completely forget a positive.. I'd always assumed we were all like that!

I find the negative reviews the most useful, not individually, but in aggregate. If several people complain about the same thing, it might actually be an issue. A well written and thoughtful negative review can also contain useful information. If the negative reviews all seem to be random bitching, however, I know the place/product/service is probably fine.

I find the negative reviews are usually the most informative. If all of a restaurant's bad reviews are about service or exceptional situations, that's a strong endorsement for the quality of the food.

Pictures of health code violations and stories of health code violations usually raise some red flags (especially if recent). Those are too easy to fake.

The most useful ones are when they go through exactly what they thought was right/wrong with the food (and a pattern emerges across the pictures and multiple reviews about different dishes).