Since you haven't linked to the specific post you are referring to, it's hard to be very specific, but in any case, looking at all of your answers, I can see you have received exactly two downvotes. This just means that two people (or even just one person who voted on both posts) out of the more than 16 thousand users with enough rep to downvote, chose to cast a downvote on two of your answers.
None of us can know who did this and only the person who did it can know why. I can tell you that as a general rule, I don't think people here tend to downvote for typos, so I really doubt your interpretation is correct. People vote for personal reasons and it's impossible to know what was in every random downvoter's mind at the time they chose to vote.
All that said, I am going to guess that you are referring to your answer here:
Why does awk's printf interpret character values greater than 127 as multi-byte characters?
As explained above, we cannot know why the person who voted chose to downvote, but I have to say it is really strange that you undid a helpful edit. I have now redone it because the edit was a clear improvement, fixed various minor language issues and didn't take anything away from your answer. Please don't undo such good edits. This is a collaborative site and if you are not comfortable with others editing your posts, especially if you object to such clearly helpful edits, then you really will not enjoy your time here since this sort of collaborative editing is a very major part of how we do things.
Anyway, I really doubt the downvote was in any way related to your typos or to the fact that you rolled back a useful edit. I would instead guess that the downvote is simply because your answer is not answering the question. It seems quite correct and interesting, but it isn't answering the question asked. The post asks:
What is the significance of 0xc280, and why does awk output that character instead of 0x80?
Your answer doesn't address this at all. Instead, it gives ways for awk to print out an arbitrary byte. Which is interesting and can be useful, but isn't an answer to the question asked.
These sites have their own set of rules which can be surprising and confusing to new users. One of the more important ones is that, unlike traditional forums, we are very strict about everything posted being either a question or an answer to the specific question. Useful and interesting discussions that are not providing a direct answer are not wanted here.
So, to answer your main question: we value correct information that provides a solution to the problem or question posed in the Question. We also value clear writing, and encourage everyone to edit each other's posts so we can ensure high quality and up to date answers as much as possible. We do not, however, welcome discussions or tangential posts no matter how true or interesting they may be. This is just not the right place for them.