Don't feel bad about feedback, its feedback! its ok to criticize flaws because that is what feedback is for!
Not like, "I feel guilty for it being mean," sort of bad.
More like, "There was little about what was good and you should keep doing," sort of feedback, which is just as important and sadly often left out (especially with me, a bad habit I am trying to fix.)
tldr; bad is in low quality, not bad as in critical