Sentence variation … absolutely acknowledged by writers around the world as a key to effective, engaging writing. And for good reason, as it keeps the text interesting. You yourself employed advanced sentence structuring in your criticism here, which negates your own point.
I disagree 100% with what you’re stating here — both in personal opinion and practice, having earned much of my living to date writing professionally. But, I would at least agree on one point your raised, which is that the misuse of alternatives to “said” can be the tip-off of an amateur. One can’t write at a 4th grade level and then simply pepper the document with out-of-context words from a thesaurus; quality writing should have a certain consistence of tone, and such variance should flow naturally.
I’m glad to get any responses, though. We need not all agree on approach or technique. I should think we could at least agree on that much. I like to think of my advice as having an asterisk above it indicating something like “take my advice and try it out; if it doesn’t work for you, try something else.” Thanks, Peter. :-)