This is in the same category as people on dating sites complaining about wanting to know why they don't get replies to their messages or people wanting an explanation of why a company chose to hire someone else and not them. They say they just want feedback so they can get better, but 999 times times out of 1000, the reality is they start a fight if you actually give feedback. They don't want to improve. They just got their feelings hurt and want a chance to defend themselves. You're not going to please everyone all of the time. Just forget about it and move on. Want to do your own sanity the best favor you can ever do it? Other than maybe one proofread immediately after submission, don't go back and look at your past comments at all. You can't worry about whether they were downvoted if you never even know they were downvoted.