The authors they attack are indies, people who do all their own writing, editing, spell and grammatical checking. Inherent in this process is that if the writer missed the error the first time, they are sadly quite likely to miss it the next ten times as well.
Outside editors can be hired, of course. Editing services cost upwards of $10 per page - more than most of my books make in a year and I actually have decent sales. Quality of editing at that price varies considerably and I've read a few indie books that had indie publishers, who thus presumably provided proof reading and editing, that still contained a number of mistakes.
Come to think of it, I've read Dick Francis books, Mary Higgins Clark books, and other books by quite famous authors with huge publishing houses behind them that contained mistakes in spelling, continuity, grammar, and other editorial boo-boos. Strangely, I've never felt the need to put those in my review, or lower a books rating for it and I haven't seen any other reviewers do it either. Speaking strictly for me, I chuckle at human error even among the big boys and carry on reading. (I admit, I know one person who takes a red pencil and marks up the book, then gives it to the library!)
But these reviewers don't feel the need to do this to the big boys - just to the little indies. Seems like a new version of trolling to me. I can't help but wonder if they are frustrated writers themselves.
As a reader. constant mistakes in every other line is disruptive to reading. If I hit a book like that, I generally just delete it from my device and go on. I have faith that in the long run the marketplace itself will discourage those writers - or better yet, they will look at their sales and seek out more learning about writing and find out for themselves what is driving their readers nuts. No need for insults or negativity from vicious reviewers.
I've been the victim of one myself, in this review here - whch finally, two years later, I've managed to reply to. Bloodline took two years to write and was meticulously gone over four or five times by myself and one or two blessed volunteer readers - mainly to work on continuity. But, clearly, we missed a few things.
However, after this nasty review was published, this book which had been puttering along with a few sales, took a nosedive and has had very few sales since even when it was offered for free or when I paid for advertising. Aside from the typical author's emotional response of feeling like I've been stabbed in the heart with a long dagger - this has hurt me financially. It has discouraged me from continuing the series - as all of the books I have in mind are going to take just as much work as Bloodline - and for what? Even though several readers have contacted me to ask for the sequel, I haven't been able to work up the courage to tackle it.
So yes, it's personal - but I've seen it done to other indie writers by other reviewers - some of them even nastier. Most Kindle readers do read those reviews and make decisions based on them.
So to those "reviewers" - and all reviewers - unless the errors are so egregious that they make it impossible to read the book smoothly - please review the story. I understand (and I'm sure all authors do) that my fiction may not appeal to everyone. (Hell, my fiction hardly appeals to anyone since I don't write romance) I can take it if you found it personally boring or not your favored style. But don't hang a two star review on someone because you found a spelling error. Would you do that to Steve Grisham? Nora Roberts? Would you sit down and write a letter to Harper Collins or Simon & Schuster enumerating their mistakes?
To our readers - you can contact the writer of most Kindle books and let us know about errors you have found. It is possible for us to correct those errors and upload a corrected version. I would thank you for it! And apologize, too, of course! If you see a nasty review, or that a book has some one and two star reviews - please check them out and consider that the reviewer may have their own agenda, or that a few spelling errors doesn't mean a book isn't a good read.
Okay, enough said.