From the critic's perspective, deciding whether or not to publicly correct a writer's spelling, punctuation error(s) is definitely a judgment call. And that is certainly not to assume that everyone uses good judgment. When such an error is within the body of an email message, random posting, etc., it is (reasonably) much tougher to criticize. When an error is discovered within the text block of a published work (such examples are uncommon, but do surface occasionally), it is more likely that the mistake was the writer's and then overlooked by the line editor, though the editing process does work both ways. My editor would admit to her own errors not found in the original manuscript. An error might constitute more of an issue, particularly if the glitch distracts the reader, or prevents them, in some way, from fully enjoying the scene, setting, dialogue, story arc, etc. And if such an issue does result, it would (again, reasonably) justify contacting the author, publisher about it. But notice that I have thus far avoided a return to the word 'publicly,' used in my opening sentence.
There are those who cannot resist an opportunity to find fault in others. It's pretty much 'Psychology 101,' or 'I can repair my own low self-esteem by chipping away at yours.' And some would jump at the chance to provide criticism because they see published writing as falling within the domain of public consumption (Hey, it's out there for everyone to see, isn't it?). It's worth noting here that professional critics get paid to do this sort of thing. Nothing personal, of course! :) There's also this: 'I mean really! I paid good money for this book!' True, we all want and deserve our money's worth. Additionally, bad editing is insulting, since reading is a personal experience. But then, writing is also very personal.
Because writing is so personal, I am inclined, actually happy, to accept private notification, correction of errors in spelling, punctuation, and/or usage in my everyday correspondence, postings, etc. Although I try very hard to avoid such mistakes! After all, I am a published author with a reputation to uphold. Where I think the average critic oversteps the 'rudeness barrier' is when they point out such everyday errors in a public arena. This is likely to embarrass, at least disconcert.
In a novel I recently read, published by a major house, there were two errors that fall under the category of 'typo.' One, I had seen before, and is more common: 'the the.' The second: 'after' spelled 'alter.' Neither had any impact on my enjoyment of the work. Rarely does one see formatting issues; a good thing, since that kind of error can really distract.
Now back to the authors mentioned at the top of the blog, and a couple more that may surprise you.
Ernest Hemingway did a good deal of journalistic reporting during the Spanish Civil War, often from the front lines of the conflict. Newspaper editors regularly complained about his miscues and spelling mistakes. His typical response to them was something like - 'Well, that's what you're paid to correct!'
Jane Austen titled one of her early works, 'Love and Freindship,' and once spelled 'scissors' as 'scissers.'
William Faulkner's editor at Random House, Albert Erskine, referring to the author's misspellings, faulty punctuation, and accidental repetitions, once said, 'He depended on me to point out such errors and correct them, and though we never achieved a perfect performance, we tried.'
F. Scott Fitzgerald's novel, 'This Side of Paradise,' was famously criticized by literary critic, Edmund Wilson, who said of the work, 'One of the most illiterate books of any merit ever published.'
In a love letter to Fanny Brawne, Keats spelled 'purple' as 'purplue.' The author tried to hide his embarrassment by claiming that he meant to coin a new word - a cross between purple and blue.
Enough examples of the human side of erring? It's reassuring to know that it has happened to the best of them, and will likely continue with today's writers. Doing the research to prepare this blog, I can say that I am as determined as ever to avoid missteps in my work, while appreciating that the foot bridge over the chasm is wobbly, my gait is unsteady, and there is no hand rail to protect me from falling!
My very best to you in writing!