As Flatt notes, sarky reviews are often more fun to read than nicey-nice ones, especially online, where "funny negatives are much more likely to go viral than gracious accolades, and bloggers seem particularly keen to avoid the smear of gentle amateurism by showcasing a rigorous vitriol."
The spiky language of insult also seems to be more interesting than the milky language of approval - take for example AA Gill's famously withering restaurant reviews.
I've recently finished reading Luca Turin and Tania Sanchez's Perfume: The Guide, a collection of reviews of over 1200 perfumes. [Part of my ongoing intellectual crush on Turin - see also here and here.] Scent is a terrifically difficult things to describe (try attaching more adjectives than 'fruity' or 'clean' to your shampoo next time you wash your hair) but Sanchez and Turin do it beautifully - from the loving tribute to the cutting one liner. But best is when they wrangle with the mysterious in-between. Here's Turin's review of Lancôme’s Trésor:
I once sat in the London Tube across a young woman wearing a t-shirt printed with headline-size words ALL THIS across her large breasts, and in small type underneath “and brains too.” That vulgar-but-wily combination seems to me to sum up Trésor. Up close, when you can read the small print, Trésor is a superbly clever accord between powdery rose and vetiver, reminiscent of the structure of Habanita. From a distance, it’s the trashiest, most good-humored pink mohair sweater and bleached hair thing imaginable. When you manage to appeal to both the reptilian brain and the neocortex of menfolk, what happens is what befell Trésor: a huge success.
In a review of Perfume: The Guide (ohhh - meta-review) John Lanchester writes: "[Turin and Sanchez’s] work is, quite simply, ravishingly entertaining, and it passes the high test that their praise is even more compelling than their criticism." And that is why I will read the book all over again. Probably soon.