This topic comes up on writing sites from time to time: the art of critiquing and the adventures of receiving critiques.
Depending on what stage my story is at, and depending on who I pass it off to, I will ask for my critiquers to approach my manuscript from specific perspectives (may contain one or more of the following): “How did I do with sentence structure?” “Can you point out typos and misspellings?” “Does the story make sense?” “Did I leave any loose ends that leave you unfulfilled or otherwise scratching your head?” “How does the story flow?” That sort of thing. Then, when it is my turn to critique something of theirs, I return the favor and the courtesy by approaching the task in whatever way that matches their preferences or concerns. If they want me to focus on character development, that is what I do. If they ask only that I find every last grammatical error I can find, that is what I do. Etc.
There is one form of critique that I have never asked for (and never will), yet I still get it at least once per manuscript: the critiquer tells me how they would have written a certain passage by actually rewriting it!
To express my dismay and confusion as eloquently as possible…ARE YOU KIDDING ME?! I’ve never even had an editor do that to me, and they’re the gateways to a contract! Whatever happened to telling me that the passage in question is too convoluted or too rambling or too off the point?…then explaining why you feel that way without doing the actual revision for me? A few years ago, before I had any publishing credits to my name, I sent a 20 page manuscript to a fellow aspiring writer; the edited version she sent back was almost double in size because of how many passages she rewrote for me. Suffice it to say, I ditched that file and sought out a different critiquer.
When I critique, I might come across a passage that screams for a rewrite, and an obvious way of doing exactly that might cross my mind, but I fully understand and accept that what I have before me is their story, not mine, so I only point them in a direction with a humble “Consider having your character do / feel / express…”, and let the writer him/herself handle the heavy lifting…because, how else are they going to learn and improve if somebody else writes it for them?