For the most part, I agree with Annabelle. A review to be useful to other travelers needs to be more comprehensive and explain why the business is good or bad. If it doesn't, as a traveler I can really assess if this is the place for me or not. What can be great for you, may not be so for me.
However, having spent the past few days reading reviews on other types of websites, I'm starting to think that there are people out there who write a review to just give a thumbs up/down to the business in general, sort of a quick thank you or hate you note to the business owner. For reviewers whose idea of a review site is to show some quick appreciation to the business, I can understand why they don't think they need to get into details.