I love reviews even the ones I will be mentioning here so don't get me wrong write reviews regardless. I was going through the new reviews I had on my books and saw one that said basically wonderful book but needs a good editor as the grammar needed work. It doesn't, not really and I will explain why in a moment. But I realised that commenting on grammar in a review is not really needed. I'll still read a book that someone said had terrible grammar because to be frank those people who mention the grammar are what I call Grammar Nazi. I hire a Grammar Nazi to do my editing so there is certainly a place for them. But not in a review and here is why.
1. Grammar is an artificial construct
Yes, you might say there are rules and we have to follow them except there aren't and we don't. There are plenty of authors who have written whole novels without a certain letter or speech marks or full stops. A writer is an artist. When you start picking at the grammar you are saying, "Well, I didn't quiet like that shade of yellow they used on the sun flowers." The author makes the rules because they are the artist. If we didn't have rule breakers we wouldn't have half the classics.
2. The rules are different around the world
A typical rule to look at that changes is the oxford comma. I'm not a fan of it but that is because I live in a part of the world where it isn't taught in schools. It is odd when I see it and stands out like a sore thumb. Spelling is the same colour and color are both right in different countries. But even in the same place there are words and rules that are both right. Focussed and focused are both right in my part of the world. Though apparently not in the US as my spell check is freaking out. What you think is set in stone is actually more like a Newtonian fluid.
3. Teachers don't know the rules
I'm a teacher and so I feel confident to say this as fact. We don't teach teachers the grammar rules. I have an English degree and they never taught nada about grammar in the three years (Yes, three not four, the rest of the world doesn't do general studies year at college instead we do that at high school) I studied. I did some grammar in primary school but that is so far back I barely remember it. I've been learning more and more grammar with my writing but I can tell you with my hand on my heart I don't teach Grammar Nazi level grammar at school. A. I don't have the time and B. It isn't on the test. C. My students won't need it.
4. When they say grammar they don't mean grammar
To me grammar is the placement of full stops and commas but when people comment on grammar what they really are commenting on is the crafting of the text. I'm a baby author and I'm still learning but even so I have my own style of writing. I'm dyslexic so when I read I don't read everything. I'm a smart cookie I can figure out what a house or a car looks like I don't have to read the two paragraph description of a creepy house to know it is creepy. What this translate into is that I cut out stuff when I write. I give just enough for people to get the tone of the text without bogging it down. Put it this way, I'm no Tolkien. Unfortunately, people who like Tolkien will read my stuff and wonder why they don't like it and notice my clunky use of commas and point to grammar as the reason they don't like my work. Be honest you just don't like my style.
5. No one cares
Well, a small minority do but the vast group of readers out there either don't know when the grammar is wrong or don't care. They want a good story. I'd rather have people comment on whether they liked the characters or the story. My best one star review that I still like is one where they said they didn't like the love interest because it reminded them of their professor from college. Perfect because my character was a professor. You might not have had a crush on one of your professors but I sure did and I know there are a lot out there. That one star will actually sell books but at least was honest instead of hiding behind grammar.
So in saying that I have come across some books that did need a serious edit but not because of grammar. But rather because of filler, filter and redundant words. Not because of the misplaced commas. Because lets be frank I wouldn't have the foggiest idea in the first place for where they should go. That is why I always hire a editor. I've seen a manuscript that was deemed 'clean' by experts which I couldn't stand because it was stick a pin in your eye boring.