Having worked as a travel agent, Thomas cook did a severy when I was with them
7/10 people would write a bad review
5/10 people would write a review if there stay was okish
And only 4/10 people would write a good review
So your more than likely to find a bad review then a good one, even though the hol was fab people just don't write them.
And remember not everyone likes the same things, and things change such as staff, weather etc
Take reviews with a pinch of salt as long as there's not 100 bad ones and no good then don't go.
Also check the date date it was written, ones written 5years ago have no reflect on today's. I'd only look at reviews for the season/the end of last season