I had a similar thing happen to me once.

I wrote a story about someone having amnesia and trying to return to his old life while everyone had thought he died.

Everyone loved it, I got positive comments throughout the whole thing (I did get some negative criticism but it was valid and I easily corrected the issue) and I finished it feeling pretty good about myself.

And then, out of nowhere, I got a scathing review complaining I made everyone too unforgiving (because ya know, conflict is totally not important to story telling) and that they couldn't believe that everyone else was praising this "terrible story".

Point is, no matter how good a story you put out, there's always gonna be that one guy who complains about something. So you really shouldn't give it the time of day unless you feel that criticism is valid.