It's not really clear why you're asking - every review site about everything has members who are nitpicky, impossible to please and/or downright bloody miseries (if not actually vindictive or malicious) just as it has members who are fair, sensible and balanced, and as Ian says, many say more about the writer than the subject.
Anybody who saw the TV programme about TripAdvisor will remember those featured who wrote horribly negative reports about hotels because there was a drop of water left in their kettle or because the sheets weren't changed every single day after they deliberately put a biro mark on one to try and catch them out. Everybody in any service industry has to suffer them and most don't get paid as much as we do

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It's not really appropriate to discuss other people's reviews here (or the people who write them, since punters cannot post here) but if you don't want to receive reviews on the site you named you can contact the admin and opt out, although that can unfortunately lead punters to think you've something to hide. A more constructive thing to do is remember that provided you're getting repeat business and your clients are happy with what you offer, it doesn't really matter what anonymous people write about you on the internet

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