So the tone is pretty matter-of-fact, but the advice isn't bad. Unless you feel your mistake is instructive, I personally would not leave it in there. It's hard to read huge blocks of strike through (
stricken through? struck through!) text, so I don't think leaving it there helps. We can see what it was in all the gory detail in the revision history if you just want to mention the mistake.
Here are a few examples from my history where I made mistakes and let the answer live on anyway:
“Hope this help” or “Hope this helps”?
Meaning of “hard society woman”
Isobel,whose brother he was..or…was he
I'm not particularly proud of my mistakes, but I think that they are OK examples of how to handle feedback that is critical. In the first question, I was obviously wrong but instead of just fixing my answer I tried to explain why I was confused. In the second one, someone pointed out that my interpretation might be wrong, and I could understand where they were coming from, but there was only one other answer. I decided not to delete my answer and just salvage as much as I could. In the last question, I honestly thought folks were getting too hung up on the gender of the name and missing the point of the question, so instead of rewriting my answer or ignoring the feedback, I included both views. If I had to do it over again, I might have just changed the name to something masculine.
My point is, how you respond to it depends on what feedback you get, but I think if it's constructive criticism there is always something you could do in response, even if it isn't exactly what someone is recommending you do. You don't have to defend your answer against every comment, but I think it's really good to respond in some way to someone who has taken the time to try to help you get more up-votes (which is how I try to view feedback on my answers).