I am not a fan of popular writers who use traditional publishers. I know a well-known alternate history writer. As soon as the traditional publisher announces a new book buy this writer coming out, many readers pre-buy the hardback and paperback. The fact it is full of typos and grammar errors doesn’t bother the writer, the traditional publisher, or the fans. If you didn’t know it was traditionally published, you would think it was someone self-publishing. I actually see some self-published authors who have far less typos than this writer.
End result, I have never purchased any of their books and I boycott the traditional publisher. That is a writer and publisher who take no pride in their work. I am not talking hubris level pride. My father taught us to do our best work. Sometimes I make a mistake and have no problem correcting it if I or someone else notices it and informs me. I am human which means I am not perfect.
I have a friend who is a diehard fanboy of the writer. My friend tries to defend the writer by claiming the writer isn’t rich. I couldn’t find out how much the writer makes, but given how popular they are, the writer makes enough to easily pay out of pocket for editors and proofreaders.
Mistakes happen, but when a popular writer at a traditional publisher has so many mistakes, the writer and the traditional publisher need to be sent a message.