I think I am one of those whose answers you edited and who rolled back to their original version. At least I rolled back an edit to one of my answers recently, and this answer refers to that.
The reason for my rollback was that someone added something to my answer with which I didn't agree.
I think that this site differs from, say, Stack Overflow in some very basic way. When you write code, there is code that works and code that doesn't work. While there are often different ways of coding the same function (so there are different correct answers to a question), there are clearly answers that are better than others, because they better do, what the OP wants, or because the code is more safe, etc.
In writing there is no such clear reference (works / doesn't work) against which you can measure an answer to a given question. First of all, no one knows which certain books sell and others don't. If we knew that, everyone would be writing bestsellers. Second, people (readers and writers) have different tastes. Third, different approaches work differently for different writers. Therefore, there never is one correct answer for any given question here. Anyone who believes that doesn't understand people (nor writing).
If you are on Stack Overflow and you see a why to improve code, most everyone will agree with that improvement. Here, it is not clear what is and what isn't an improvement. Therefore you are showing respect for and understanding of people's differences, by politely writing a comment suggesting your improvement, and allowing the author (!) of the answer to either accept and include that improvement or leave it as a comment for others to add to the answer in their minds if they agree with you.
I stressed the word "author" here, because that is also a difference. Software (or academic writing) is almost always a communal effort. While every programmer is proud of their contribution, they work with a mindset that includes teamwork. A fiction writer on the other hand is usually the sole creator of his work. He or she not only takes pride in their work, as the programmer (or contributor to a scientific publication) does, but indentifies with their work because they express their personality in their writing.
Authors feel the same way about their answers here, because this perspective is not limited to their novels, but a personality trait. I deeply dislike anyone messing with what I wrote, because you basically mess with me. I expect them to discuss their objections with me, allowing myself to change my opinion (and myself). I am always open to that, but reserve the right to disagree.
My recommendation would be to do what I do:
If you see and answer that you mostly agree with but would like to add something to or correct in some detail, write a comment.
If your own answer differs fundamentally from the answers given, write your own answer.
Do not write a near duplicate of another answer, even if your own wording would be better. That's stealing. You can write that you agree with so-and-so, but want to add this or that. Give credit where credit is due.
Do not change the meaning of answers, that's disrespectful.
Only correct spelling, grammar or confusing wording, but don't go overboard with that either, we're not a school, but a help forum.
Finally, I'd like to say that I very much appreciate your contributions to this site and that I find many of your answers helpful. I didn't even think your (if it was yours) edit to my question was basically wrong. It just wasn't the answer that I wanted to give. I upvoted this question, because I think its a great one and gave me an opportunity to clarify my own behavior on this site for me. Thank you.