I don't recall ever saying using the wrong dialogue tags is the cardinal sin of writing, which I opine is plagiarism.
However, you don't have to use dialogue tags to introduce nuances. "He said affectionately"...sure, you get the idea that was he said was spoken with an affectionate tone, but what exactly do you see--or in this case hear--as a reader? Affection? Affection is an emotional response to external stimuli, a nuance that we're spoon feeding the reader. I'm sorry if you don't agree, but from what I've been taught throughout my young life, what I've heard from published writers, what I've learned through personal experience, is that one should rarely, if ever, tell an emotion, you show it. Whether you use body language, a nervous tick the character might have, or simply the context of the scene to show it, an emotion should not be told. Saying "He was sad" doesn't show the reader anything. Yes, he is sad, but what is sad? Crying? Head dipped? Large frown? The reader only sees sad, but doesn't see what the character is actually going through in the scene.
When I said one shouldn't be taken seriously as a writer, I meant this person hasn't read enough, written enough, and learned enough, to understand how to show "affection" without having to tell it. Someone who knows what they're doing should be able to write an entire novel-length ms by using said just about 80% of the time, if not more, and should never have to use a single "emotion describing" word, such as sad, upset, depressed, affectionately, and the such.
I'm not saying I'm above anyone--far from it. In fact, I'll readily admit that, in the past, I've done the very thing I'm advising against, using distracting quotes tags in the place of better writing. It's a lesson I've been been fortunate enough to have been taught early, both by myself (through reading and writing) and professionals who have been there and done that.
Yes, such tags have been used in successful books. Some good, some not so good. Mind you, successful does not inherently mean worth your time--Twilight can sell a billion copies, that does not make it a well written piece of art. Unfortunately, and this is true especially for American literature, the culture writers live in too often caters to people like Stephanie Meyer and Clive Cussler, who opt for cheap melodrama, misogyny, and lazy characterization that is easily accessible but without substance (convenient for a popcorn flick society), and, because of this, they sell millions of books.
The way I see it, the writer constantly learns, and never stops learning. As it should be. As people, we should always strive to continuously teach ourselves new ways to expand our understanding of things.
See you!
