Tbh, that different understanding doesn't matter much if you have enough reviews since it averages out.

If you compare two products with one review each, then yes, it hugely matters whether the one reviewer considered 5 stars as "expectations fullfilled" or "the best thing that happened to me ever".

But if you got >1k reviews, both sides will get equal amounts of both reviewer groups and it will average out so that both products will be compareable based on their stars.

That's a big misunderstanding many people have in regards to reviews. Many people are also afraid that unfair reviewers will skew the score. But since these unfair reviewers are usually spread equally over all products, it averages out as soon as you have a couple hundred reviews.

And that's also what that article criticises. It's much more important how many reviews an article has than the exact value. It's easy to get a straight 5-star rating if you have only a single review. It's much harder to do so if you have 10k reviews.

So the information value is: <100 or so reviews, the rating means little to nothing. >1000 reviews it can be usually trusted.